Digital video recording/playback system with entry point processing function

ABSTRACT

This invention allows the user to insert an entry point (bookmark) at an arbitrary recording position of video data, audio data, and the like as if he or she placed a bookmark between pages of a book. Information RTR_VMG that manages recorded objects includes movie cell entry point information M_C_EPI. M_C_EPI includes entry point playback time information EP_PTM and text information PRM_TXTI that pertains to an entry point. PRM_TXTI can store text information that pertains to its contents together with type information and date information of an entry point.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 11-131475, filed May 12, 1999,the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus/method capable ofreal-time digital recording of a video picture and the like, and adigital information medium (real-time digital video recording/playbacksystem) used in the apparatus/method.

More particularly, the present invention relates to an apparatus/methodwhich assures a special information storage area on arecordable/reproducible DVD disc (DVD-RAM disc or the like), and usesinformation stored in that area as needed upon playback, erasure, or thelike of a recorded video program.

Nowadays, DVD video specification that uses MPEG2 (Moving Picture ExpertGroup 2) in video (moving picture) digital recording/playback, and AC-3(Digital Audio Compression or Audio Coding 3) in audio digitalrecording/playback has been settled, and various playback apparatuses(DVD video players) which use that specification are commerciallyavailable.

The DVD video specification supports MPEG2 as a moving picturecompression scheme, and AC-3 audio and MPEG audio in addition to linearPCM as an audio recording scheme. Also, the DVD video specificationsupports sub-picture data for superimposed dialogs, navigation data forplayback control such as fastforwarding, rewinding, data search, and thelike, and ISO9660 and UDF bridge format for computers.

Furthermore, recordable DVD discs (recordable/reproducibleDVD-RAM/DVD-RW or write-once DVD-R) have been developed, and anenvironment that allows the development of digital video informationrecording/playback apparatuses (alternatives to a conventional videocassette tape recorder) using recordable DVD discs is in order.

Under such circumstances, the DVD-RTR (DVD real-time recording)specification for digitally recording a video picture or the like inreal time and playing it back has been proposed, and is settled as astandard.

However, the number and kinds of program contents recorded tends toincrease with increasing recording size of a disc, and it becomes harderfor the user to grasp the recorded contents. For this reason, a problemis posed in terms of management of recorded discs.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide an apparatus/methodand medium, which allow the user to write or erase a mark (entry point)at an arbitrary recording position of video data, audio data, and thelike as if he or she placed a bookmark between pages or at an importantposition while reading a book.

In order to achieve the above object, a digital video information mediumaccording to the present invention has a volume space including amanagement area and data area.

The data area stores data segmented into one or more objects(RTR_MOV.VRO/VR_MOVIE.VRO, RTR_STO.VRO/VR_STILL.VRO,RTR_STA.VRO/VR_AUDIO.VRO). Each object is comprised of one or more dataunits (one or more VOBUs form a cell, and one or more cells form videoobject). Each data unit (VOBU) stores one or more packs (video or audiopacks) of video or audio data to be played back within a predeterminedtime (0.4 to 1.2 sec).

The management area stores management information (RTR_VMG) used tomanage the objects. The management information (RTR_VMG) has programchain information (ORG_PGCI or UD_PGCIT) for designating the playbackorder of objects. The program chain information (PGCI) includes one ormore pieces of program information (PGI) and one or more pieces of cellinformation (CI). The cell information (CI) contains designationinformation (M_CI) for designating an object to be played back.

The designation information (M_CI) records entry point information(M_C_EPI) for designating the playback position in an object.

The entry point information (M_C_EPI) includes information (PRM_TXTI)that pertains to an entry point.

In order to achieve the above object, a digital video informationrecording/playback apparatus according to the present invention recordsor plays back the contents of the objects (RTR_MOV.VRO/VR_MOVIE.VRO)using a recordable/reproducible medium which has movie cell information(M_CI) in management information (RTR_VMG) for managing objects (RTR₁₃MOV.VRO/VR_MOVIE.VRO) as recorded information.

The digital video information recording/playback apparatus comprises anentry point setting unit (MPU) for setting a required entry point(M_C_EPI#1 to M_C_EPI#n) in the movie cell information (M_CI); anadditional information input unit (MPU) for inputting additionalinformation (information type, information date, text information, andthe like in PRM_TXTI) with respect to the entry point (M_C_EPI); and anadditional information setting unit (MPU) for setting the additionalinformation in the entry point (M_C_EPI).

In order to achieve the above object, a digital video informationprocessing method according to the present invention records or playsback the contents of the objects (RTR_MOV.VRO/VR_MOVIE.VRO) using arecordable/reproducible medium which has movie cell information (M_CI)in management information (RTR_VMG) for managing objects(RTR_MOV.VRO/VR_MOVIE.VRO) as recorded information.

In this digital video information processing method, a required entrypoint (M_C_EPI#1 to M_C EPI#n) is set in the movie cell information(M_CI); additional information (information type, information date, textinformation, and the like in PRM_TXTI) is input with respect to theentry point (M_C_EPI); and the additional information is set in theentry point (M_C_EPI).

Using the entry point as needed, the user can easily recognize therecorded contents of a disc. Also, using the entry point information,the user can record/play back from a desired position.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe invention, and together with the general description given above andthe detailed description of the preferred embodiments given below, serveto explain the principles of the invention.

FIG. 1 is a view for explaining the structure of arecordable/reproducible optical disc according to an embodiment of thepresent invention;

FIG. 2 is a view for explaining the format of digital informationrecorded on the optical disc shown in FIG. 1;

FIG. 3 is a view for explaining the data structure of a video objectshown in FIG. 2;

FIG. 4 is a view for explaining the data structure of a dummy pack shownin FIG. 3;

FIG. 5 is a view for explaining the file structure of digitalinformation recorded on the optical disc shown in FIG. 1;

FIG. 6 is a view for explaining the data structure of a navigation datafile (RTR_VMG) shown in FIG. 5; FIG. 7 is a view for explaining thecontents of a video manager information table (VMGI_MAT) shown in FIG.6;

FIG. 8 is a view for explaining the data structure of a play list searchpointer table (PL_SRPT) shown in FIG. 6;

FIG. 9 is a view for explaining the contents of play list search pointertable information (PL_SRPTI) shown in FIG. 8;

FIG. 10 is a view for explaining the contents of a play list searchpointer (PL_SRP) shown in FIG. 8;

FIG. 11 is a view for explaining the contents of thumbnail pointerinformation (THM_PTRI) shown in FIG. 10;

FIG. 12 is a view for explaining the data structure of a movie AV fileinformation table (M_AVFIT) shown in FIG. 6;

FIG. 13 is a view for explaining the data structure of movie VOBinformation (M_VOBI) shown in FIG. 12;

FIG. 14 is a view for explaining the data structure of time mapinformation (TMAPI) shown in FIG. 13;

FIG. 15 is a view for explaining the contents of time map generalinformation (TMAP_GI) shown in FIG. 14;

FIG. 16 is a view for explaining the contents of a time entry (TM_ENT)shown in FIG. 14;

FIG. 17 is a view for explaining the data structure of a user definedPGC information table (UD_PGCIT) shown in FIG. 6;

FIG. 18 is a view for explaining the data structure of a text datamanager (TXTDT_MG) shown in FIG. 6;

FIG. 19 is a view for explaining the data structure of PGC information(PGCI; original PGC or user defined PGC information);

FIG. 20 is a view for explaining the contents of PGC general information(PGC_GI) shown in FIG. 19;

FIG. 21 is a view for explaining the contents of program information(PGI) shown in FIG. 19;

FIG. 22 is a view for explaining the data structure of cell information(CI) shown in FIG. 19;

FIG. 23 is a view for explaining the data structure of movie cellinformation (M_CI) shown in FIG. 22;

FIG. 24 is a view for explaining the contents of movie cell generalinformation (M_C_GI) shown in FIG. 23;

FIG. 25 is a view for explaining the contents of movie cell entry pointinformation (M_C_EPI) shown in FIG. 23;

FIG. 26 is a view for explaining a use example of primary textinformation (PRM_TXTI);

FIG. 27 is a view for explaining a correspondence among programs thatform a program set, and program parts that form a play list;

FIG. 28 is a view for explaining a correspondence between thepresentation start times/presentation end times of cells that form auser defined PGC (or original PGC), and the offset addresses for VOBUsof VOBs that form a movie video object (RTR_MOV.VRO/VR_MOVIE.VRO) shownin FIG. 5;

FIG. 29 is a block diagram for explaining an example of the arrangementof an apparatus (RTR video recorder) for recording a video program orthe like in real time and playing it back using therecordable/reproducible optical disc shown in FIG. 1;

FIG. 30 is a flow chart for explaining an example of recording in theapparatus shown in FIG. 29;

FIG. 31 is a flow chart for explaining an example of playback in theapparatus shown in FIG. 29;

FIG. 32 is a flow chart for explaining an example of an entry pointenter process in the apparatus shown in FIG. 29;

FIG. 33 is a flow chart for explaining an example of an automatic entrypoint enter process (for entering entry points at given time intervals)in the apparatus shown in FIG. 29;

FIG. 34 is a flow chart for explaining an example of a text informationinput process in the apparatus shown in FIG. 29;

FIG. 35 shows an example of a text information input window in the textinformation input process shown in FIG. 34;

FIG. 36 is a view for explaining an example of the relationship amongrecorded video data, entry points, and information (attribute, recordingdate, and the like) of the recorded video data in an optical discrecorded by the apparatus shown in FIG. 29;

FIG. 37 is a view for explaining another example of the relationshipamong recorded video data, entry points, and information (attribute,recording date, and the like) of the recorded video data in an opticaldisc recorded by the apparatus shown in FIG. 29;

FIG. 38 is a flow chart showing an example of a playback menu displayprocess in the apparatus shown in FIG. 29;

FIG. 39 shows an example of a playback menu display window in theplayback menu display process shown in FIG. 38;

FIG. 40 is a flow chart for explaining an example of a text informationsearch process in the apparatus shown in FIG. 29;

FIG. 41 shows an example of a search keyword input window in the textinformation search process shown in FIG. 40;

FIG. 42 shows an example of a search result display window in the textinformation search process shown in FIG. 40;

FIG. 43 is a flow chart for explaining an example of a defect enterprocess in the apparatus shown in FIG. 29;

FIG. 44 is a view for explaining an example of the relationship betweendefective portions of recorded video data detected by the process shownin FIG. 43, and entry points;

FIG. 45 shows a display example of defective portions of recorded videodata detected by the process shown in FIG. 43, and their reproductionmanners;

FIG. 46 is a flow chart for explaining an example of a process forentering the priority order of erasure in the apparatus shown in FIG.29;

FIG. 47 is a view for explaining an example of the relationship amongrecorded video data, entry points, and information (attribute, recordingdate, and the like) of the recorded video data detected by the processshown in FIG. 46;

FIG. 48 shows a display example of information (recording time, title,thumbnail, last playback date, and the like) of recorded video datadetected by the process shown in FIG. 46, and its order of erasure;

FIG. 49 explains a structure of one stream pack used when a streamer isused for a DVD-RTR recorder;

FIG. 50 shows details of the inner structure of the stream pack shown inFIG. 49;

FIG. 51 briefly illustrates entry point relating information withrespect to movie cell information (M_CI) used for an RTR recorder;

FIG. 52 briefly illustrates entry point relating information withrespect to still picture cell information (S_CI) used for an RTRrecorder; and

FIG. 53 briefly illustrates entry point relating information withrespect to stream cell information (SCI) used for a streamer.

DETAILED DESCRIPTION OF THE INVENTION

The arrangement of a medium (DVD recordable/reproducible disc) accordingto an embodiment of the present invention, the arrangement of a DVD-RTR(DVD real-time recording) recording/playback apparatus (RTR videorecorder), and various operations of this apparatus will be explainedbelow with reference to the accompanying drawings.

FIG. 1 is a view for explaining the structure of optical disc 10 used inthe DVD-RTR recording/playback apparatus. As shown in FIG. 1, opticaldisc 10 has a structure obtained by adhering a pair of transparentsubstrates 14 respectively having layers 17A and 17B using adhesivelayer 20.

If this disc 10 is a single-layered DVD-RAM (or DVD-RW) disc, firstinformation recording layer 17A is formed of a phase change recordinglayer, and second information recording layer 17B is formed of a dummylayer (which may also serve as a label of that disc).

If this disc 10 is a single-sided, two-layered DVD-ROM/RAM disc, firstinformation recording layer 17A is formed of a semi-transparent film(thin metal film or the like) formed with pits, and second informationrecording layer 17B is formed of a phase change recording layer.

If this disc 10 is a double-sided, two-layered DVD-RAM (or DVD-RW) disc,both first and second information recording layers 17A and 17B areformed of phase change recording layers.

Each substrate 14 can be formed of a 0.6-mm thick polycarbonate film,and adhesive layer 20 can consist of a very thin ultraviolet settingresin (around 40 m to 70 m thick). When this pair of 0.6-mm thicksubstrates 14 are adhered so that layers 17A and 17B contact each otheron the surfaces of adhesive layer 20, 1.2-mm thick large-capacityoptical disc 10 is obtained.

Optical disc 10 has center hole 22, and clamp areas 24 used for clampingoptical disc 10 upon its rotation are formed around center hole 22 onthe two surfaces of the disc. Center hole 22 receives the spindle of adisc motor when disc 10 is loaded into a disc drive (not shown). Opticaldisc 10 is clamped at its clamp areas 24 by a disc damper (not shown).

Optical disc 10 has information areas 25 that can record informationsuch as video data, audio data, and the like around clamp areas 24.

Each information area 25 has lead-out area 26 on its outer peripheryside, and lead-in area 27 on its inner periphery side that contactsclamp area 24. The area between lead-out and lead-in areas 26 and 27 isdefined as data recording area 28.

FIG. 1 also exemplifies the correspondence between each data recordingarea 28 of optical disc 10 and a data recording track recorded there.

On each of recording layers 17A and 17B of information areas 25, arecording track is continuously formed in, e.g., a spiral pattern. Thecontinuous track is segmented into a plurality of sectors, which haveserial numbers. Various data are recorded on optical disc 10 using thesesectors as recording units.

Data recording area 28 serves as an actual data recording area, andrecords video data (main picture data) such as a movie or the like,sub-picture data such as superimposed dialogs, menus, and the like, andaudio data such as words, effect sounds, and the like asrecording/playback information in the form of similar pit trains(physical shapes or phase states that bring about change in opticalconditions).

When optical disc 10 is a double-sided recording RAM disc in which eachsurface has one recording layer, each of recording layers 17A and 17Bcan be formed by three layers, i.e., by sandwiching a phase-changerecording material layer (e.g., Ge2Sb2Te5) between two zincsulfide-silicon oxide (ZnS.SiO2) mixture layers.

When optical disc 10 is a single-sided recording RAM disc in which eachsurface has one recording layer, recording layer 17A on the side ofread-out face 19 can be formed by three layers including theaforementioned phase-change recording material layer. In this case,layer 17B on the side opposite to read-out face 19 need not be aninformation recording layer but may merely be a dummy layer.

When optical disc 10 is a one-side read type two-layered RAM/ROM disc,two recording layers 17A and 17B can comprise single phase-changerecording layer 17B (on the side farther from read-out face 19;read/write), and single semi-transparent metal reflection layer 17A (onthe side closer to read-out face 19; read-only).

When optical disc 10 is a write-once DVD-R, a polycarbonate substrate isused, gold can be used as a reflection layer (not shown), and anultraviolet setting resin can be used as a protection layer (not shown).In this case, an organic dye is used in recording layer 17A or 17B. Asthe organic dyes, cyanine, squarilium, chroconic, and triphenylmenthanedyes, xanthene and quinone dyes (naphthoquinone, anthraquinone, and thelike), metal complex dyes (phthalocyanine, porphyrin, dithiol complex,and the like), and so forth can be used.

Data can be written on such DVD-R disc using a semiconductor laserhaving a wavelength of 650 nm and an output of around 6 to 12 mW.

In various types of optical discs 10 described above, read-only ROMinformation is recorded on the recording layer as an embossed patternsignal. By contrast, no such embossed pattern signal is formed onsubstrate 14 having a read/write (or write-once) recording layer, and acontinuous groove is formed instead. A phase-change recording layer isformed on such groove. In case of a read/write DVD-RAM disc, thephase-change recording layer in land portions is also used forinformation recording in addition to the groove.

When optical disc 10 is of one-side read type (independently of one ortwo recording layers), substrate 14 on the rear side viewed fromread-out face 19 need not always be transparent to the read/write laserbeam used. In this case, a label may be printed on the entire surface ofsubstrate 14 on the rear side.

A DVD-RTR recorder/player (to be described later) can be designed toattain repetitive recording/repetitive playback (read/write) for aDVD-RAM disc (or DVD-RW disc), single recording/repetitive playback fora DVD-R disc, and repetitive playback for a DVD-ROM disc.

When disc 10 is a DVD-RAM (or DVD-RW), disc 10 itself is stored incartridge 11 to protect its delicate disc surface.

When DVD-RAM disc 10 in cartridge 11 is inserted into the disc drive ofa DVD-RTR recorder/player (to be described later), disc 10 is pulled outfrom cartridge 11, is clamped by the turntable of a spindle motor (notshown), and is rotated to face an optical head (not shown).

On the other hand, when disc 10 is a DVD-R or DVD-ROM, disc 10 itself isnot stored in cartridge 11, and bare disc 10 is directly set on the disctray of a disc drive.

Recording layer 17 of information area 25 shown in FIG. 1 is formed witha continuous data recording track in a spiral pattern. The continuoustrack is segmented into a plurality of logical sectors (minimumrecording units) each having a given storage size, as shown in FIG. 1,and data are recorded with reference to these logical sectors. Therecording size per logical sector is determined to be 2,048 bytes (or 2kbytes) which are equal to one pack data length (to be described later).

Data recording area 28 is an actual data recording area, which similarlyrecords management data, main picture (video) data, sub-picture data,and audio data.

Note that data recording area 28 of disc 10 can be segmented into aplurality of ring-shaped (annular) recording areas (a plurality ofrecording zones), although not shown. The disc rotational velocityvaries in units of recording zones. However, within each zone, aconstant linear or angular velocity can be set. In this case, anauxiliary recording area (free space) can be provided for each zone.These free spaces in units of zones may collectively form a reserve areafor that disc 10.

FIG. 2 is a view for explaining the hierarchical structure ofinformation recorded on optical disc 10 shown in FIG. 1.

In this structure, lead-in area 27 includes an embossed data zone whoselight reflection surface has an embossed pattern, a mirror zone whosesurface is flat (mirror surface), and a rewritable data zone capable ofinformation rewrites. Lead-out area 26 is also made up of a rewritabledata zone capable of information rewrites.

Data recording area (volume space) 28 is comprised of volume/filemanagement information 70 and data area DA, which can be rewritten bythe user.

Volume/file management information 70 records file information ofaudio/video data recorded on data area DA, and information that pertainsto the entire volume.

Data area DA can have both areas DA1 and DA3 that record computer data,and audio/video data area DA2 that records video data/audio data and thelike. Note that the recording order, recording information size, and thelike of computer data and audio/video data are arbitrary. Data area DAcan record computer data or audio/video data alone.

Audio/video data area DA2 includes control information DA21, videoobject DA22, picture object DA23, and audio object DA24.

Control information DA21 can include control information required uponexecuting various processes such as recording (image recording and/oraudio recording), playback, edit, search, and the like.

Video object DA22 can include information of the contents of recordedvideo data.

Picture object DA23 can include still image information such as stillimages, slide images, and the like.

Audio object DA24 can include information of the contents of recordedaudio data.

Note that video object DA22 is formed by video object set VOBS. ThisVOBS has contents corresponding to one or more program chains PGC#1 toPGC#k which respectively designate cell playback orders by differentmethods.

The embossed data zone of lead-in area 27 records in advance:

(1) information which pertains to the entire information storage medium:the disc type (a DVD-ROM, DVD-RAM (or DVD-RW), DVD-R, or the like); discsize (12 cm, 8 cm, or the like); recording density; physical sectornumbers indicating the recording start/end positions, and the like;

(2) information which pertains to the recording/playback/erasurecharacteristics: the recording power and recording pulse width; erasepower; playback power; linear velocity upon recording and erasure, andthe like; and

(3) information which pertains to the manufacture of each informationstorage medium: the manufacturing number and the like.

The rewritable zone of each of lead-in area 27 and lead-out area 26includes:

(4) a field for recording a unique disc name of each informationrecording medium;

(5) a test recording field (for confirming recording/erasureconditions); and

(6) a field for recording management information that pertains todefective fields in data area DA.

On fields (4) to (6), a DVD-RTR recorder/player (a RTR video recorder ora personal computer with a DVD-RAM drive) can record information.

When disc 10 is set in the DVD-RTR recorder/player (RTR video recorder),information on lead-in area 27 is read first. Lead-in area 27 records apredetermined reference code and control data in ascending order ofsector numbers.

The reference code in lead-in area 27 is made up of two error correctioncode blocks (ECC blocks). Each ECC block consists of 16 sectors. Thesetwo ECC blocks (32 sectors) are generated by appending scramble data.Upon playing back the reference code appended with the scramble data,filter operation or the like on the playback side is done to play back aspecific data symbol (e.g., 172), thus assuring data read precisionafter that.

The control data in lead-in area 27 is made up of 192 ECC blocks. Thiscontrol data field repetitively records the contents for 16 sectors ineach block 192 times.

This control data made up of 16 sectors contains physical formatinformation in the first sector (2,048 bytes), and disc manufacturinginformation and contents provider information in the subsequent sectors.

The physical format information contained in the control data includesthe following contents.

That is, the first position describes the version of the DVD format thatthe recorded information complies with.

The second position describes the size (12 cm, 8 cm, or the like) of arecording medium (optical disc 10) and minimum read-out rate. In case ofa read-only DVD video, 2.52 Mbps, 5.04 Mbps, and 10.08 Mbps areprescribed minimum read-out rates, but other minimum read-out rates arereserved. For example, when an RTR video recorder capable of variablebit rate recording records at an average bit rate of 2 Mbps, the minimumread-out rate can be set to fall within the range from 1.5 to 1.8 Mbpsusing the reserve field.

The third position describes the disc structure (the number of recordinglayers, track pitch, recording layer type, and the like) of therecording medium (optical disc 10). Based on this recording layer type,disc 10 can be identified to be a DVD-ROM, DVD-R, or DVD-RAM (orDVD-RW).

The fourth position describes the recording density (linear density andtrack density) of the recording medium (optical disc 10). The lineardensity indicates the recording length per bit (0.267 μm/bit, 0.293μm/bit, or the like). on the other hand, the track density indicates theneighboring track spacing (0.74 μm/track, 0.80 μm/track, or the like).The fourth position also includes a reserve field to designate othernumerical values as the linear density and track density of a DVD-RAM orDVD-R.

The fifth position describes the start and end sector numbers and thelike of data area (volume space) 28 of the recording medium (opticaldisc 10).

The sixth position describes a burst cutting area (BCA) descriptor. ThisBCA is applied as an option to a DVD-ROM disc alone, and is an area forstoring recorded information upon completion of the disc manufacturingprocess.

The seventh position describes a free space size of the recording medium(optical disc 10). For example, when disc 10 is a single-sidedsingle-layered recording DVD-RAM disc, information indicating 2.6 GB (orthe number of sectors corresponding to this number of bytes) is storedat that position of disc 10. On the other hand, when disc 10 is adouble-sided recording DVD-RAM disc, information indicating 5.2 GB (orthe number of sectors corresponding to this number of bytes) is storedat that position.

Other positions are reserved for future use.

FIG. 3 is a view for explaining the data structure of the video objectshown in FIG. 2.

As shown in FIG. 3, each cell (for example, cell #m) consists of one ormore video object units (VOBUs). Each VOBU is constituted as a set (packsequence) of video packs, sub-picture packs, audio packs, dummy packs,and the like.

Each of these packs has a predetermined size (2,048 bytes) and serves asa minimum unit for data transfer. The minimum unit for logicalprocessing is a cell, and logical processing is done is units of cells.

The playback or presentation time of the VOBU corresponds to that ofvideo data made up of one or more picture groups (groups of pictures; tobe abbreviated as GOPs) included in the VOBU, and is set to fall withinthe range from 0.4 sec to 1.2 sec. One GOP is screen data which normallyhas a presentation time of about 0.5 sec in the MPEG format, and iscompressed to play back approximately 15 frame images during thisinterval. (The VOBU includes an integer number of GOPs except for aspecial case wherein a gap is produced in the video data flow. That is,the VOBU is normally a video information compression unit synchronouswith GOPs.)

When the VOBU includes video data, a video datastream is formed byarranging GOPs (complying with MPEG) each consisting of video packs,sub-picture packs, audio packs, and the like. However, independently ofthe number of GOPS, the VOBU is defined with reference to thepresentation time of GOPs.

Note that even playback data consisting of audio data and/or sub-picturedata alone is formed using the VOBU as one unit. For example, when theVOBU is formed by audio packs alone, audio packs to be played back inthe presentation time of the VOBU to which the audio data belong arestored in that VOBU as in the video object of video data.

The packs that form each VOBU have similar data structures except for adummy pack. An audio pack will be taken as an example. As shown in FIG.3, a pack header is allocated at the beginning of the pack, a packetheader and sub-stream ID follow, and audio data is allocated at the endof the pack. In such pack format, the packet header is written withinformation of presentation time stamp PTS indicating the start time ofthe first frame in the packet.

Likewise, a pack that stores real-time recording data can be made up ofa pack header, a packet header that can contain PTS information andstuffing bytes as needed, and a data area that stores video, audio,sub-picture, or real-time recording data. At the end of this data area,padding bytes can be appended as needed.

The pack header can contain data such as a pack start code, system clockreference (SCR), program multiplex rate, pack stuffing length, and thelike.

In a DVD-RTR recorder/player that can record a video program thatcontains video object DA22 with the structure shown in FIG. 3 on opticaldisc 10, the user often wants to edit the recording contents afterrecording. In order to meet such requirement, dummy packs can beappropriately inserted in each VOBU. Each dummy pack can be used torecord edit data later.

The dummy pack shown in FIG. 3 has a data structure shown in FIG. 4.More specifically, one dummy pack 89 is comprised of pack header 891,packet header 892 having a predetermined stream ID, and padding data 893padded with a predetermined code (insignificant data). Note that packetheader 892 and padding data 893 form padding packet 890. The contents ofpadding data 893 in a non-used dummy pack are not especiallysignificant.

This dummy pack 89 can be used as needed when the recording contents areto be edited after predetermined image recording is done on disc 10shown in FIG. 1, and in other cases.

More specifically, the dummy pack is inserted into each VOBU for thepurposes of:

addition of information to be additionally recorded after imagerecording (for example, memo information indicating that after-recordinginformation is inserted into an audio pack and replaced by a dummy packis inserted as sub-picture information into a sub-picture pack and isreplaced by a dummy pack);

compensation of a short size from an integer multiple of 32 kbytes tomatch the VOBU size with an integer multiple of the ECC block size (32kbytes); and so forth.

Also, the dummy pack can be used to store reduced-scale image (thumbnailpicture) data which is displayed on a user menu, as needed.

FIG. 5 is a view for explaining an example of the directory structure ofinformation (data files) recorded on the optical disc shown in FIG. 1 tohave the data structure shown in FIG. 2.

According to the DVD-RTR specification capable of digital real-timerecording/playback of a video picture, the contents of a DVD disc aremanaged using the directory structure shown in FIG. 5, and are saved inaccordance with a file system such as ISO9660, UDF, or the like.

Even when the data structure shown in FIG. 2 is used on thedisc/apparatus side, this data structure is invisible to the user. Thedata structure that the user can actually see is a hierarchical filestructure shown in FIG. 5.

More specifically, directories such as a DVD_RTR directory, VIDEO_TSdirectory, AUDIO_TS directory, computer data file directory, and thelike are displayed on the display screen (not shown) of the rootdirectory by means of menu windows, icons, or the like in correspondencewith the types of data recorded on data area DA shown in FIG. 2.

The DVD_RTR directory shown in FIG. 5 stores file RTR.IFO of navigationdata RTR_VMG, file RTR_MOV.VRO/VR_MOVIE.VRO of movie video objectRTR_MOV.VOB, file RTR_STO.VRO/VR_STILL.VRO of still picture video objectRTR_STO.VOB, file RTR_STA.VRO/VR_AUDIO.VRO of still picture additionalaudio object RTR_STA.VOB for still pictures, and the like.

Note that file RTR.IFO stores management information such as a programset, program, entry point, play list, and the like for managing movingpicture information.

File RTR_MOV.VRO/VR_MOVIE.VRO stores recorded moving picture informationand its audio information, file RTR_STO.VRO/VR_STILL.VRO stores recordedstill picture information and its audio information, and fileRTR_STA.VRO/VR_AUDIO.VRO stores after-recording data for a stillpicture, and the like.

When a DVD-RTR recorder/player (RTR video recorder) has a function ofdisplaying the directories shown in FIG. 5 and also has a playbackfunction of a DVD video disc (ROM disc), and the DVD video disc is setin its disc drive, the VIDEO_TS directory shown in FIG. 5 is activated.In this case, when the VIDEO_TS directory is opened, the recordedcontents of the set disc are further displayed.

When the DVD-RTR recorder/player has a DVD audio playback function and aDVD audio disc is set in its disc drive, the AUDIO_TS directory shown inFIG. 5 is activated. In this case, when the AUDIO_TS directory isopened, the recorded contents of the set disc are further displayed.

Furthermore, when the DVD-RTR recorder/player comprises a personalcomputer with a DVD-RAM drive and has a computer data processingfunction, and a DVD-RAM (or DVD-ROM) disc that has recorded computerdata is set in that disc drive, the computer data directory shown inFIG. 5 is activated. In this case, when the computer data directory isopened, the recorded contents of the set disc are further displayed.

The user can access the recorded sources of DVD video, DVD video ROM,DVD audio, and computer data (including computer programs) as if he orshe were operating a personal computer, while observing a menu screen orwindow display screen displayed with the directory structure shown inFIG. 5.

FIG. 6 is a view for explaining the data structure of the navigationdata file (RTR_VMG) shown in FIG. 5. RTR video manager RTR_VMG asnavigation data is comprised of various kinds of information, as shownin FIG. 6.

Referring to FIG. 6, RTR video manager information RTR_VMGI describesbasic information of recordable/reproducible optical disc (RTR disc) 10shown in FIG. 1. This RTR_VMGI contains video manager informationmanagement table VMGI_MAT and play list search pointer table PL_SRPT.

RTR_VMGI further contains movie AV file information table M_AVFIT, stillpicture AV file information table S_AVFIT, original PGC informationORG_PGCI, user defined PGC information table UD_PGCIT, text data managerTXTDT_MG, and manufacturer's information table MNFIT.

FIG. 7 shows the contents of the video manager information managementtable (VMGI_MAT) shown in FIG. 6.

Referring to FIG. 7, VMG identifier VMG_ID describes “DVD RTR_VMG0” thatspecifies an RTR_VMG file using an ISO646 character set code.

RTR_VMG_EA describes the end address of RTR_VMG by a relative bytenumber from the first byte of RTR_VMG.

VMGI EA describes the end address of RTR_VMGI by a relative byte numberfrom the first byte of RTR_VMG.

VERN describes the version number of the DVD specification for videorecording (real-time video recording).

TM_ZONE describes the time zone of the RTR disc. In the DVD_RTRspecification, five different data fields (PL_CREATE_TM, VOB_REC_TM,FIRST_VOB_REC_TM, LAST_VOB_REC_TM, and VOBU_REC_TM) are specified. Thesefive different data fields are generally called REC_TM. REC_TM containsdata TZ_TY and TZ_OFFSET. TZ_TY describes a common universal time orlocal time, and TZ_OFFSET describes a date offset from the commonuniversal time in units of minutes.

STILL_TM describes the still time of a still picture in units ofseconds.

CHRS describes a character set code used in primary text information.With this CHRS, for example, an ISO8859-1 character set code or shiftJIS kanji code can be designated.

RSM_MRKI describes program chain number PGCN, program number PGN, cellnumber CN, marker point MRK_PT, and marker creation time MRK_TM. PGCN inthis information indicates the number of the program chain where amarker point is present. When a marker is present in an original PGC,PGCN is set at “0”. PGN indicates the number of the program where themarker point is present. When a resume marker is present in a userdefined PGC, PGN is set at “0”. CN indicates the number of a cell wherethe marker point is present. MRK_PT indicates a marker point in a targetcell. When the resume marker is present in a movie cell, MRK_PTdescribes a presentation time (PTM) using an RTR presentation timedescription format. MRK_TM describes the time of creation of the markerusing an RTR date description format.

REP_PICTI describes program chain number PGCN, program number PGN, cellnumber CN, picture point PICT_PT, and representative picture creationtime CREAT_TM of the disc.

PGCN in this information indicates the number of the program chain wherea representative picture of the disc is present. The representativepicture of the disc is designated by only the pointer in an originalPGC. Hence, when this representative picture pointer is present, PGCN isset at “0”. PGN indicates the number of the program where therepresentative picture of the disc is present. When a resume marker ispresent in a user defined PGC, PGN is set at “0”. CN indicates thenumber of a cell where the representative picture of the disc ispresent. PICT_PT indicates the representative picture of the disc in thetarget cell. When the representative picture is present in a movie cell,PICT_PT describes the presentation time (PTM) using the RTR presentationtime description format. When this representative picture is present ina still picture cell, PICT_PT describes a still picture VOB entry number(S_VOB_ENTN) in a corresponding still picture VOB group (S_VOG).CREAT_TM describes the time of creation of the representative picture ofthe disc using the RTR date description format.

M_AVFIT_SA describes the start address of movie AV file informationtable M_AVFIT shown in FIG. 6 by a relative byte number from the firstbyte of RTR_VMG.

S_AVFIT_SA describes the start address of still picture AV fileinformation table S_AVFIT shown in FIG. 6 by a relative byte number fromthe first byte of RTR_VMG.

ORG_PGCI_SA describes the start address of original PGC informationORG_PGCI shown in FIG. 6 by a relative byte number from the first byteof RTR_VMG.

UD_PGCIT_SA describes the start address of user defined PGC informationtable UD_PGCIT shown in FIG. 6 by a relative byte number from the firstbyte of RTR_VMG. If UD_PGCIT is not available, UD_PGCIT_SA is set at“0000 0000h”.

TXTDT_MG_SA describes the start address of text data manager TXTDT MGshown in FIG. 6 by a relative byte number from the first byte ofRTR_VMG. If TXTDT_MG is not available, TXTDT_MG_SA is set at “00000000h”.

MNFIT_SA describes the start address of manufacturer's information tableMNFIT shown in FIG. 6 by a relative byte number from the first byte ofRTR_VMG. If MNFIT is not available, MNFIT_SA is set at “0000 0000h”.

FIG. 8 shows the data structure of play list search pointer tablePL_SRPT shown in FIG. 6.

PL_SRPT describes information required for searching and accessing playlists in an RTR disc, and contains play list search pointer tableinformation PL_SRPTI and one or more play list search pointers PL_SRP#1to PL_SRP#n.

Each play list is made up of a user defined PGC, and each PL_SRP has aPGC number corresponding to that play list.

Each play list is specified by play list number PLN assigned thereto.PLNs are assigned to all pointers PL_SRP, and have serial numbers from 1to 99 (maximum) in the order of one or more pointers PL_SRP described inPL_SRPT.

The user can identify a specific play list from other ones using PLN. Orthe user can identify a specific play list from other ones using textinformation appended to the play list.

FIG. 9 shows the contents of play list search pointer table informationPL_SRPTI shown in FIG. 8.

PL_SRP_Ns indicates the number of play list search pointers PL_SRP inPL_SRPT.

PL_SRPT_EA indicates the end address of play list search pointer tablePL_SRPT, which is described by a relative byte number from the firstbyte of PL_SRPT.

FIG. 10 shows the contents of play list search pointer PL_SRP shown inFIG. 8.

Referring to FIG. 10, PL_TY describes the play list type. That is, oneof movie, still picture, or hybrid (both movie and still picture) playlists can be specified by the contents (4-byte PL_TYL) of PL_TY.

PGCN describes the number of corresponding user defined program chainUD_PGC. The maximum value of this PGCN is 99.

PL_CREATE_TM describes the time of creation of the play list using theRTR date description format. This PL_CREATE_TM can describe year, month,day, hour, minute, and second.

PRM_TXTI describes primary text information of the play list. ThisPRM_TXTI consists of 128 bytes, the first 64 bytes of which are used todescribe primary text information using ASCII character sets, and theremaining 64 bytes of which are used to describe primary textinformation using other character sets (shift JIS, ISO8859-15, and thelike). Other character set codes are described in VMGI_MAT, and can beused by all pieces of primary text information in the disc. Note that aterminal control code is not described in PRM_TXTI.

IT_TXT_SRPN describes the number of IT_TXT_SRP of the play list. (Itemtext IT_TXT will be described later with reference to FIG. 18.)

THM_PTRI describes information of thumbnail pointer THM_PTR. Thumbnailpointer information THM_PTRI may be optionally set or used in either anRTR recorder and player. If the RTR recorder does not have performancecapable of processing THM_PTRI, all pieces of 8-byte THM_PTRI can be setat “FFh”. If the RTR player does not have performance capable ofprocessing THM_PTRI, it may simply ignore THM_PTRI. Note that a“thumbnail” means a picture as small as the nail of the thumb, andnormally indicates a picture which is obtained by reducing a stillpicture in a recorded video picture to the thumbnail size.

FIG. 11 shows the contents of thumbnail pointer information THM_PTRIshown in FIG. 10. Referring to FIG. 11, CN describes the number of acell where the thumbnail point is present. Also, THM_PT describes thethumbnail point in a target cell.

When the resume marker is present in a movie cell, THM_PT describes thepresentation time (PTM) using the RTR presentation time descriptionformat.

When a thumbnail is present in a still picture cell, THM_PT describes astill picture VOB entry number (S_VOB_ENTN) in a corresponding stillpicture VOB group (S_VOG).

FIG. 12 shows the data structure of the movie AV file information table(M_AVFIT) shown in FIG. 6.

M_AVFIT describes information of a movie AV file (fileRTR_MOV.VRO/VR_MOVIE.VRO shown in FIG. 5), and contains movie AV fileinformation table information M_AVFITI, one or more pieces of movie VOBstream information M_VOB_STI#1 to M_VOB_STI#n, and movie AV fileinformation M_AVFI.

M_AVFI is information of a movie AV file having a predetermined filename (RTR_MOV.VRO/VR_MOVIE.VRO), and contains movie AV file informationgeneral information M_AVFI_GI, one or more movie VOB information searchpointers M_VOBI_SRP#1 to M_VOBI_SRP#n, and one or more pieces of movieVOB information M_VOBI#1 to M_VOBI#n.

One movie AV file can contain one or more VOBS, and each VOB has movieVOB information M_VOBI for VOB in M_AVFI. One or more pieces ofinformation M_VOBI in M_AVFI are described in the same order as that ofVOB data stored in the movie AV file.

FIG. 13 shows the data structure of the movie VOB information M_VOBIshown in FIG. 12. As shown in FIG. 13, M_VOBI contains movie VOB generalinformation M_VOBI GI, seamless information SMLI, audio gap informationAGAPI, and time map information TMAPI.

M_VOBI_GI shown in FIG. 13 contains VOB_TY which describes the type ofVOB, VOB_REC_TM which describes the recording time of the start field inVOB using the RTR date description format, VOB_REC_TM_SUB whichdescribes the recording time (sub-second information) of the start fieldin VOB by the number of video fields, M_VOB_STIN which describes thenumber of movie VOB stream information, VOB_V_S_PTM which describes thepresentation start time of the first video field in VOB using the RTRpresentation time description format, and VOB_V_E_PTM which describesthe presentation end time of the last video field in the VOB using theRTR presentation time description format.

VOB_TY includes TE which indicates if that VOB has been temporarilyerased, A0_STATUS which indicates the status of audio stream #0,Al_STATUS which indicates the status of audio stream #1, analogprotection system APS which indicates the format of analog copyprotection or the ON/OFF state of this copy protection, SML_FLG whichindicates if VOB is to be played back seamlessly, AO_GAP_LOC whichindicates if an audio gap is present in audio stream #0 and the locationof the audio gap if it is present, and Al_GAP_LOC which indicates if anaudio gap is present in audio stream #1 and the location of the audiogap if it is present.

VOB_REC_TM is updated to indicate the recording time of the start fieldof the remaining VOB if the start field of a given VOB is deleted(erased).

More specifically, “new VOB_REC_TM=old VOB_REC_TM+presentation durationof deleted field”.

On the other hand, if the presentation duration of the deleted fieldcannot be displayed in units of seconds (for example, when thepresentation duration of the deleted field is 60.5 sec),

“new VOB_REC_TM+new VOB_REC_TM_SUB=old VOB_REC_TM+oldVOB_REC_TM_SUB+presentation duration of deleted field”.

Since VOB_REC_TM describes the date of video recording, even when audiodata has been modified, such modification has no influence onVOB_REC_TM.

The aforementioned RTR date description format will be briefly explainedbelow. In this format, presentation time PTM is expressed by a PTM baseand PTM extension. The PTM base is a value measured using 90 kHz as aunit, and the PTM extension is a value measured using 27 MHz as a unit.

SMLI shown in FIG. 13 contains VOB_FIRST_SCR which describes SCR (systemclock reference) of the first pack of current VOB using the RTRpresentation time description format, and PREV_VOB_LAST_SCR whichdescribes SCR of the last pack in previous VOB using the RTRpresentation time description format.

FIG. 14 shows the data structure of the time map information TMAPI shownin FIG. 13. Time map information TMAPI is used upon executing specialplayback (e.g., cell playback in an order unique to each user using auser defined PGC) and time search.

Time map information TMAPI includes time map general informationTMAP_GI, one or more time entries TM_ENT#1 to TM_ENT#r, and one or moreVOBU entries VOBU_ENT#1 to VOBU_ENT#q.

Each VOBU entry contains information of the size and presentation timeof VOBU. The VOBU size is presented in units of sectors (2 kbytes), andthe presentation time is presented in units of video fields (onefield=1/60 sec in NTSC; one field=1/50 sec in PAL).

Since the VOBU size is presented in units of sectors, as describedabove, VOBU can be accessed using addresses in units of sectors.

Each VOBU entry includes reference picture size information 1STREF_SZ,VOBU playback time information VOBU_PB_TM, and VOBU size informationVOBU_SZ.

Note that VOBU_PB_TM represents the playback time of VOBU of interest inunits of video fields. On the other hand, reference picture sizeinformation 1STREF_SZ represents the size of the first reference picture(corresponding to I-picture in MPEG) of VOBU of interest in units ofsectors.

On the other hand, each time entry contains address information(VOBU_ADR) of the corresponding VOBU, and time difference information(TM_DIFF). This time difference information indicates the differencebetween the playback time designated by the time entry and the VOBUpresentation start time.

Assuming that the time interval (time unit TMU) between two successivetime entries is 10 sec, this time entry interval corresponds to 600fields in, e.g., NTSC video.

Normally, the “time interval between neighboring VOBUs” is expressed bythe number of fields in the VOBU entry. As another method, a “countvalue from a given VOBU to the next VOBU by a clock counter” may be usedto express the “time interval between neighboring VOBUS”.

For example, the “time interval between neighboring VOBUs” can beexpressed by the “difference value between the value of presentationtime stamp at the start position of one VOBU and the value of PTS at thestart position of the immediately succeeding VOBU”.

In other words, “the time interval in a specific unit can be expressedby the difference value of the clock counter in that unit”.

FIG. 15 shows the contents of time map general information TMAP_GI shownin FIG. 14.

This time map general information TMAP_GI includes TM_ENT_Ns indicatingthe number of time entries in that time map information, VOBU_ENT_Nsindicating the number of VOBU entries in that time map information, timeoffset TM_OSF for that time map information, and address offset ADR_OFSof that time map information.

When a value (10 sec or equivalent) corresponding to 600 fields in NTSCvideo (or 500 fields in PAL video) is used as time unit TMU, time offsetTM_OSF is used to represent the time offset within TMU.

When the VOBU size is expressed by the number of sectors, address offsetADR_OFS is used to indicate a file pointer from the beginning of an AVfile.

FIG. 16 shows the contents of time entry TM_ENT shown in FIG. 14.

This time entry TM_ENT includes VOBU_ENTN indicating the number of thecorresponding VOBU entry, TM_DIFF indicating the time difference betweenthe presentation start time of VOBU designated by the time entry, andthe calculated presentation time, and VOBU_ADR indicating the targetVOBU address.

When time unit TMU is expressed by 600 fields in NTSC (or when time unitTMU is expressed by 500 fields in PAL), the “calculated presentationtime” with respect to time entry #j is given by TMU (j−1)+TM_OSF.

On the other hand, VOBU_ADR indicates the target VOBU address by thetotal size of VOBUs preceding VOBU of interest when the VOBU size isexpressed in units of sectors.

In the aforementioned data structure, in order to start presentationfrom the middle of a certain VOBU, that access point must be determined.This access point is assumed to be a time entry point.

This time entry point is located at a position separated from theposition indicated by movie address information of VOBU by the timedifference indicated by time difference information TM_DIFF in timeentry TM_ENT. This time entry point serves as a special presentationstart point (or time search point) indicated by time map informationTMAPI.

FIG. 17 shows the data structure of user defined PGC information tableUD_PGCIT shown in FIG. 6.

UD_PGCIT includes user defined PGC information table informationUD_PGCITI, one or more user defined PGCI search pointers UD_PGCI_SRP#1to UD_PGCI_SRP#n, and one or more pieces of user defined PGC informationUD_PGCI#1 to UD_PGCI#n.

All UD_PGCs are assigned program chain numbers PGCN ranging from 1 to 99in the description order of UD_PGCI_SRP in UD_PGCIT. This PGCN canspecify each PGC.

UD_PGCITI contains UD_PGCI_SRP_Ns indicating the number of UD_PGCI_SRPS,and UD_PGCIT_EA indicating the end address of UD_PGCIT.

Note that the maximum value of UD_PGCI_SRP_Ns is set at, e.g., “99”.UD_PGCIT_EA represents the end address of UD_PGCIT by a relative bytenumber from the first byte of UD_PGCIT.

UD_PGCI_SRP includes start address UD_PGCI_SA of UD_PGCI. ThisUD_PGCI_SA represents the start address of UD_PGCI by a relative bytenumber from the first byte of UD_PGCIT.

FIG. 18 shows the data structure of text data manager TXTDT_MG shown inFIG. 6.

TXTDT_MG contains text data information TXTDTI, one or more item textsearch pointers IT_TXT_SRP#1 to IT_TXT_SRP#n, and one or more item textsIT_TXT.

TXTDTI includes CHRS that describes a character set code (ISO8859-1 orshift JIS kanji) used in TXTDT_MG, IT_TXT_SRP_Ns that describes thenumber of pointers IT_TXT_SRP, and TXTDT_MG_EA that describes the endaddress of TXTDT_MG by a relative byte number from the first byte ofTXTDT_MG.

Each IT_TXT_SRP includes IT_TXT_SA that desribes the start address ofIT_TXT by a relative byte number from the first byte of TXTDT_MG.

IT_TXT describes item text by a character code designated by CHRS. Thedata length (the number of bytes) of IT_TXT changes depending on thetext contents.

FIG. 19 shows the data structure of the PGC information PGCI(information of an original PGC or user defined PGC).

PGCI contains navigation information for program chain PGC.

Two different types of program chains, i.e., an original PGC and userdefined PGC, are available (see the contents of RTR_VMG shown in FIG.6). The original PGC has VOB and PGCI. However, the user defined PGCdoes not have its own VOB, and refers to VOB in the original PGC.

As shown in FIG. 19, PGC information (PGCI#i) includes PGC generalinformation PGC_GI, one or more pieces of program information PGI#1 toPGI#m, one or more cell information search pointers CI_SRP#1 toCI_SRP#n, and one or more pieces of cell information CI#1 to CI#n.

Note that the start address of cell information CI can be indicated byCI_SA described by a relative byte number from the first byte of PGCI.

FIG. 20 shows the contents of PGC general information PGC_GI shown inFIG. 19.

This PGC_GI contains PG_Ns that describes the number of programs in PGC,and CI_SRP_Ns that describes the number of CI_SRPs in PGC.

In case of the user defined PGC, PG_Ns is set at “0”. On the other hand,the maximum number of programs PG in the original PGC is “99”, and themaximum number of cells in the PGC is “999”.

FIG. 21 shows the contents of program information PGI shown in FIG. 19.

This PGI includes PG_TY which describes the type of program, C_Ns whichdescribes the number of cells in PG, primary text information PRM_TXTIused in PG, search pointer number IT_TXT_SRPTN of IT_TXT where text datacorresponds to PG, and thumbnail pointer information THM_PTRI.

Note that PRM_TXTI is constructed by a 128-byte field, and the first 64bytes of that field are described by an ASCII character set. When ASCIItext is less than 64 bytes, “00h” is written in blank bytes.

The second 64 bytes of the 128-byte field are used to describe primarytext of another character set (e.g., shift JIS or ISO8859-15). Note thatthe code of “another character set” is described in VMGI_MAT, and isshared by all the pieces of primary text information in the disc.

Note that a terminal control code that assumes a value ranging from“01h” to “1Fh” is never described in PRM_TXTI.

THM_PTRI describes information of a thumbnail pointer. That is, THM_PTRIincludes CN that describes the number of the cell where the thumbnailpointer is present, and THM_PT that describes the thumbnail point in thetarget cell.

When the resume marker is present in a movie cell, THM_PT describes thepresentation time (PTM) using the RTR presentation time descriptionformat.

On the other hand, when a thumbnail is present in a still picture cell,THM_PT describes a still picture VOB entry number (S_VOB_ENTN) in acorresponding still picture VOB group (S_VOG).

THM_PTRI may be optionally set or used in either an RTR recorder orplayer. When the RTR recorder does not have performance capable ofprocessing THM_PTRI, all the pieces of 8-byte THM_PTRI may be set at“IFFh”. On the other hand, when the RTR player does not have performancecapable of processing THM_PTRI, it may simply ignore THM_PTRI.

FIG. 22 shows the data structure of cell information CI shown in FIG.19. As shown in FIG. 22, there are two kinds of cell information, i.e.,movie cell information M_CI and still picture cell information S_CI.

Information (M_C_EPI) that pertains to the entry point is written inmovie cell information M_CI in navigation data file RTR.IFO shown inFIG. 5.

FIG. 23 shows the data structure of movie cell information M_CI shown inFIG. 22. As shown in FIG. 23, M_CI contains movie cell generalinformation M_C_GI, and one or more pieces of movie cell entry pointinformation M_C_EPI#1 to M_C_EPI#n.

FIG. 24 shows the contents of movie cell general information M_C_GIshown in FIG. 23.

That is, M_C_GI contains C_TY which describes the type of cell, M_VOBISRPN which describes the number of the movie VOBI search pointercorresponding to VOB of this cell, C_EPI_Ns which describes the numberof pieces of cell entry point information, C_V_S_PTM which describes thepresentation start time of this cell using the RTR presentation timedescription format, and C_V_E_PTM which describes the presentation endtime of this cell using the RTR presentation time description format.

Note that C_V_S_PTM and C_V_E_PTM satisfy the following conditions.

(1) In case of cell in original PGC

C_V_S_PTM must be set in the first four VOBUs of the corresponding VOB;and

C_V_S_PTM must be set in the last four VOBUs of the corresponding VOB.

(2) In case of cell in user defined PGC

O_C_V_S_PTM≦C_V_S_PTM<C_V_EPTM≦O_C_V_E_PTM must hold,

where O_C_V_S_PTM indicates the presentation start time of an originalcell corresponding to VOB referred to by this cell, and O_C_V_E_PTMindicates the presentation end time of an original cell corresponding toVOB referred to by this cell.

FIG. 25 shows the contents of movie cell entry point information M_C_EPIshown in FIG. 23.

This M_C_EPI has two types (type 1 and type 2). M_C_EPI of type 1without any text information is composed of EP_TY and EP_PTM, andM_C_EPI of type 2 with text information is composed of EP_TY, EP_PTM,and PRM_TXTI. FIG. 25 shows M_C_EPI of type 2.

As shown in FIG. 25, M_C_EPI includes EP_TY that describes the type ofentry point, EP_PTM that describes the presentation time of the entrypoint using the RTR presentation time format, and PRM_TXTI thatdescribes primary text information and the like of the entry point.

Upon playback, the value EP_PTM and cell playback time are convertedinto file pointers that point to VOBU by the time map TMAP information(see FIGS. 14 to 16), and are also converted into physical addresses bythe file system.

PRM_TXTI in M_C_EPI is constructed by a 128-byte field. The first 64bytes of that field are used to describe primary text using an ASCIIcharacter set. When ASCII text is less than 64 bytes, “00h” fills blankbytes. The latter 64 bytes of the 128-byte field are used to describeprimary text of another character set (e.g., shift JIS, ISO8859-15, orthe like). Note that “another character set” is described in VMGI_MAT,and is shared by all the pieces of primary text information in the disc.

Note that a terminal control code that assumes a value ranging from“01h” to “1Fh” is never described in PRM_TXTI.

EP_TY in M_C_EPI is comprised of 1-byte data including a 2-bit typeidentification code. If this identification code is “00b”, it indicatesthat M_C_EPI is of type 1 (empty primary text data or no data); if thecode is “01b”, it indicates that M_C_EPI is of type 2 (primary textdata).

This EP_TY has a 6-bit reserved field in addition to the 2-bit typeidentification code that identifies type 1 or 2. Using some or all thebits of this reserved field, the contents of PRM_TXTI in M_C_EPI can befurther specified. (If all the six bits are used, a maximum of 64different specifications may be made. More than 6 bits may be assignedto this designation code to specify more types.)

The bits using this reserved field will be referred to as a designationcode for designating the contents of the primary text informationhereinafter.

Specific bits in the designation code can designate whether PRM_TXTI inM_C_EPI shown in FIG. 25 is “text information” with “information type”and/or “information date” or “text information” without “informationtype” and/or “information date”.

Furthermore, specific bits in the designation code can designate whetherPRM_TXTI in M_C_EPI shown in FIG. 25 is “text information” withcorresponding “thumbnail information” in addition to “information type”and/or “information date”, or “text information” without “thumbnailinformation”. (The “thumbnail information” corresponds to, e.g.,thumbnail pointer information THM_PTRI shown in FIG. 21.)

Moreover, specific bits in the designation code can designate whetherPRM_TXTI in M_C_EPI shown in FIG. 25 consists of “thumbnail information”alone without any “text information” or “thumbnail information” with“text information”.

When the designation code (not shown) in EP_TY designates “informationtype”, “information date”, and text information” shown in FIG. 25, thesepieces of information can be used to express the following contents.

More specifically, “information type” describes an attribute of theentry point, “information date” describes the date the entry point wasentered (recorded on the disc), and “text information” describesadditional information (a brief comment of a picture at the entry point)that pertains to the entry point.

The attributes of the entry point described in “information type”include:

information type [1]=0, user mark (the user enters an entry point)

information type [1]=1; set mark (the recorder/player enters an entrypoint)

information type [1]=2; defect start mark

information type [1]=3; defect end mark

information type [1]=4; presentation start mark

information type [1]=5; presentation end mark

information type [1]=6; erasure prohibition mark

information type [1]=7; another mark (e.g., an instruction from otherthan the user or recorder/player).

Note that [1] in information type [1] means the first data field of theinformation type. If this data field has a 3-bit configuration,information type [1] can express eight different marks.

Note that information similar to “information type”, and “informationdate” and/or “text information” in FIG. 25 may be assured in play listsearch pointer PL_SRP shown in FIG. 10.

The DVD-RTR system can process text information other than the textmanaged by text data manager TXTDT_MG shown in FIG. 18. The textinformation includes primary text information (FIG. 21) described in aprogram, primary text information (FIG. 10) described in a play list,and primary text information (FIG. 25) described in the selected entrypoint.

The user uses such primary text information PRM_TXTI to identify thecorresponding recorded contents using a character set such as ASCII,shift JIS, or the like.

FIG. 26 shows that example. That is, the player (RTR recorder/player)reads out primary text information PRM_TXTI shown in FIG. 21 from disc10, and displays recording date information of recorded programs (PG1,PG2, PG3, . . . ) on the display panel of the player (this exampleindicates that recording of program #1 was started from PM 12:30:15).

When the corresponding primary text information PRM_TXTI is read outfrom the disc, the player outputs the result on a monitor (television).Before the beginning of playback of the recorded programs (PG1, PG2,PG3, . . . ), brief comments (e.g., “barbecue with family” of PG1, “7thbirthday of daughter” of PG2, and the like) of the programs recorded onthat disc 10 are displayed on the monitor screen.

The user can easily select a desired program (e.g., “barbecue withfamily) from this display. When the user has selected a desired programby operating the cursors of a remote controller (not shown) and haspressed a playback button, playback of program #1 is started.

Also, the user can similarly make display/user selection/playbackoperation using primary text information PRM_TXTI (FIG. 10) of a playlist, and those using primary text information PRM_TXTI (FIG. 25) of anentry point.

More specifically, as exemplified in FIG. 27, an entry point(corresponding to a “bookmark” compared to a book) can be set at anarbitrary position of each program, and text such as “barbecue withfamily” can be stored in primary text information PRM_TXTI (FIG. 25) ofthat entry point.

The same applies to a case wherein the user decomposes recorded programs#1 to #4 into arbitrary parts, enters the playback order of decomposedparts in play lists #1 and #2, and sets entry points in the individualparts.

Furthermore, a short title such as “barbecue with grandma” may bewritten in primary text information PRM_TXTI (FIG. 10) of each playlist.

FIG. 28 is a view for explaining a correspondence between thepresentation start times/presentation end times of cells that form auser defined PGC (or original PGC), and the offset addresses for VOBUsof VOBs that form movie video object RTR_MOV.VRO/VR_MOVIE.VRO shown inFIG. 5.

Referring to FIG. 28, information PGCI and information M_VOBI are storedin the RTR.IFO file shown in FIG. 5. A VOB as a set of VOBUscorresponding to a PGC as a set of cells is stored in theRTR_MOV.VRO/VR_MOVIE.VRO file shown in FIG. 5.

Program chain information PGCI of the original PGC shown in FIG. 28manages the playback method of a program as a set of one or more cells,and each user defined PGC manages the playback method of a set of one ormore cells determined by the user.

The presentation start time and presentation end time of each cell inthe original PGC or user defined PGC are converted by time mapinformation TMAPI contained in each M_VOBI#i shown in FIG. 13 into filepointers from the beginning of the VRO file, which point to a given VOBUthat stores the corresponding video data or the like, and are furtherconverted into physical addresses by the file system.

In order to play back each cell, the corresponding VOB number,presentation start time, and presentation end time are described as cellinformation. Upon playing back each cell, the presentation start and endtimes are passed on to the corresponding VOBI, are converted into filepointers that point to a VOBU corresponding to the cell playback timeusing a time map (TMAP) included in the VOBI, and are further convertedinto physical addresses by the file system, thus accessing a VOB.

For example, video data (VOBS) recorded in audio/video data area DA2 inFIG. 2 is made up of a set of one or more program chains PGC. Each PGCis a set of programs as sets of one or more cells, and cells to beplayed back and their order upon forming programs can be determined bythe original PGC information or user defined PGC information.

The playback times of cells and their playback order designated by theoriginal PGC information or user defined PGC information are convertedinto VOBU addresses that form each of cells to be played back on thebasis of the contents (time map TMAP shown in FIG. 28) of time mapinformation TMAPI shown in FIG. 14.

That is, upon playback based on the original PGC (the cell playbackorder of the initially recorded state), the addresses of VOBUs withinthe time band to be played back are obtained via time map information(TMAP) in accordance with the contents of ORG_PGCI shown in FIG. 6, andplayback is made in that order. on the other hand, upon playback basedon a PGC uniquely defined by the user (e.g., when the user has editedthe playback order after recording), the addresses of VOBUs within thetime band to be played back are obtained via time map information (TMAP)in accordance with the contents of UD_PGCI shown in FIG. 17, andplayback is made in that order.

The cell playback order based on user defined PGC information UD_PGCIcan be quite different from that based on original PGC informationORG_PGCI.

The playback times and the addresses of VOBUs to be played back cancorrespond to each other with reference to the contents of time entriesand VOBU entries in time map information TMAPI shown in FIG. 14.

FIG. 29 is a block diagram for explaining an example of the arrangementof an apparatus (RTR video recorder) for recording a video program inreal time and playing it back using recordable/reproducible optical disc10 shown in FIG. 1.

The apparatus main body of the RTR video recorder shown in FIG. 29 isroughly constructed by a disc drive unit (32, 34, and the like) forrotating DVD-RAM or DVD-R disc 10 and reading/writing information ondisc 10, encoder unit 50 which constructs the recording side, decoderunit 60 which constructs the playback side, and microcomputer block 30for controlling the operations of the overall apparatus.

Encoder unit 50 comprises ADC (analog-to-digital converter) 52, videoencoder (V encoder) 53, audio encoder (A encoder) 54, sub-pictureencoder (SP encoder) 55, formatter 56, and buffer memory 57.

ADC 52 receives an external analog video signal+external analog audiosignal from AV input section 42, or analog TV signal+analog audio signalfrom TV tuner 44, or the like. This ADC 52 converts the input analogvideo signal into digital data at, e.g., a sampling frequency=13.5 MHzand the number of quantization bits=8.

Likewise, ADC 52 converts the input analog audio signal into digitaldata at, e.g., a sampling frequency=48 kHz and the number ofquantization bits =16.

When an analog video signal and digital audio signal are input to ADC52, the digital audio signal passes through ADC 52.

On the other hand, when a digital video signal and digital audio signalare input to ADC 52, these signals pass through ADC 52.

A digital video signal component from ADC 52 is supplied to formatter 56via video encoder (V encoder) 53. Also, a digital audio signal componentfrom ADC 52 is supplied to formatter 56 via audio encoder (A encoder)54.

V encoder 53 has a function of converting the input digital video signalinto a digital signal compressed at variable bit rate on the basis ofthe MPEG2 or MPEG1 specifications.

A encoder 54 has a function of converting the input digital audio signalinto a digital signal (or linear PCM digital signal) compressed at fixedbit rate on the basis of the MPEG or AC-3 specifications.

When a DVD video signal is input from AV input section 42, or when a DVDvideo signal is broadcasted and is received by TV tuner 44, a teletextsignal component in the DVD video signal is input to SP encoder 55.Sub-picture data input to SP encoder 55 is arranged into a predeterminedsignal format, and is then sent to formatter 56.

Formatter 56 executes predetermined signal processing of the input videosignal, audio signal, sub-picture signal, and the like using buffermemory 57 as a work area, and outputs recording data that matches apredetermined format (file structure) to data processor 36.

Standard encode process contents for generating the recording data willbe briefly explained below. More specifically, when encoder unit 50shown in FIG. 29 starts an encode process, parameters required forencoding video data and the like are set. Main picture data ispre-encoded using the set parameters to compute optimal code amountdistribution for the selected average transfer rate (recording rate).Then, the main picture data is encoded based on the code amountdistribution obtained by pre-encoding. At this time, audio data isencoded simultaneously.

As a result of pre-encoding, if it is determined that the datacompression amount is insufficient (a desired video program cannot fallwithin a DVD-RAM disc or DVD-R disc to be used in recording), andpre-encoding can be re-done (if the source to be recorded is a sourcethat can be repetitively played back such as a video tape, video disc,or the like), main picture data is partially re-encoded, and thepreviously pre-encoded main picture data portion is replaced by there-encoded main picture data portion. With a series of processesdescribed above, the main picture and audio data are encoded, and theaverage bit rate value required for recording can be greatly reduced.

Analogously, parameters required for encoding sub-picture data are set,and encoded sub-picture data is generated.

The encoded main picture, audio, and sub-picture data are combined, andare converted into the DVD_RTR video structure.

The encoded main picture data, audio data, and sub-picture data aresegmented into packs each having a predetermined size (2,048 bytes), asshown in FIG. 3. Dummy packs are inserted into these packs, as needed.Note that time stamps such as PTS (presentation time stamp), DTS (decodetime stamp), and the like are described in packs other than dummy packs,as needed. As for PTS of sub-picture data, a time arbitrarily delayedfrom PTS of main picture data or audio data in the identical playbacktime band can be described.

Data cells are arranged in units of VOBUs to allow playback in the timecode order of data, thus forming a VOB consisting of a plurality ofcells. An RTR_MOV.VRO/VR_MOVIE.VRO file that combines one or more VOBsis formatted into the structure shown in FIG. 5.

Upon digitally copying a DVD playback signal from the DVD video player,since the contents of the cells, program chains, management tables, timestamps, and the like are determined in advance, they need not be createdagain. (However, upon designing the RTR video recorder to be able todigitally copy a DVD playback signal, the recorder must have copyrightprotection means such as digital watermarking means and the like.)

The disc drive unit that reads/writes (records and/or plays back)information to/from DVD disc 10 comprises disc drive 32, temporarystorage buffer 34, data processor 36, and system time counter (or systemtime clock; STC) 38.

Temporary storage buffer 34 is used to buffer a given amount of data tobe written on disc 10 (data output from encoder unit 50) via disc drive32, and to buffer a given amount of data played back from disc 10 (datainput to decoder unit 60) via disc drive 32.

For example, when temporary storage buffer 34 comprises a 4-Mbytesemiconductor memory (DRAM), it can buffer recording or playback datafor approximately 8 seconds at an average recording rate of 4 Mbps. Whentemporary storage buffer 34 comprises a 16-Mbyte EEPROM (flash memory),it can buffer recording or playback data for approximately 30 seconds atan average recording rate of 4 Mbps. Furthermore, when temporary storagebuffer 34 comprises a 100-Mbyte, very small HDD (hard disc), it canbuffer recording or playback data for 3 minutes or more at an averagerecording rate of 4 Mbps.

Temporary storage buffer 34 can also be used to temporarily storerecording information when disc 10 is used up during recording, untilthat disc 10 is exchanged with a new disc.

When disc drive 32 uses a high-speed drive (a speed equal to or higherthan double speeds), temporary storage buffer 34 can also be used totemporarily store readout data exceeding an amount read out from anormal drive per unit time. When temporary storage buffer 34 buffersreadout data upon playback, even when an optical pickup (not shown) hascaused read errors due to vibration shock or the like, playback databuffered by temporary storage buffer 34 can be used instead, thuspreventing the playback picture from being discontinued.

If an external card slot (not shown in FIG. 29) is provided to the RTRvideo recorder, the EEPROM can be offered as an option IC card. On theother hand, if an external drive slot or SCSI interface is provided tothe RTR video recorder, the HDD can be offered as an option extensiondrive.

When a personal computer is used as a DVD video recorder by software(not shown), the free area of a hard disc drive or a main memory of thepersonal computer itself can be partially used as temporary storagebuffer 34 shown in FIG. 29.

Data processor 36 in FIG. 29 supplies DVD_RTR recording data fromencoder unit 50 to disc drive 32, receives a DVD_RTR playback signalplayed back from disc 10, rewrites management information (some filedata in FIG. 5) recorded on disc 10, and deletes data (some or all offiles) recorded on disc 10, under the control of microcomputer block 30.

Microcomputer block 30 includes an MPU (or CPU), a ROM written withcontrol programs and the like, and a RAM which provides a work arearequired for executing programs.

The MPU of this microcomputer block 30 (to be also referred to as MPU 30hereinafter) executes, using its RAM as a work area, an entry pointenter process, text information input process, playback menu displayprocess, text information search process (recorded content searchprocess), defect enter process, priority order of erasure enter process,and the like, in accordance with the control programs stored in its ROM.

In these processes, data (a text input of a short title of the recordedcontents or the like) input by the RTR video recorder user is suppliedfrom information input unit 100 to MPU 30. Information input unit 100can use a keyboard of a personal computer or cursor keys/ten-key pad ofa remote controller (not shown).

Of the execution results of MPU 30, the contents the user of the DVD_RTRvideo recorder should know are displayed on display unit 48 of theDVD_RTR video recorder. Such message contents are also displayed on amonitor display using on-screen display (OSD), sub-picture data, and thelike, as needed.

Note that the control timings of disc drive 32, data processor 36, andencoder unit 50 and/or decoder unit 60 by MPU 30 can be determined basedon time data supplied from STC 38 (video recording/playback are normallyexecuted in synchronism with time clocks from STC 38, but otherprocesses may be executed at timings independently of STC 38).

Furthermore, MPU 30 can process the recorded dates of individualprograms recorded on disc 10, entered dates of entry points, and thelike on the basis of time data from timepiece unit 40.

Decoder unit 60 comprises separator 62 for separating and extracting therespective packs from DVD_RTR playback data with the pack structureshown in FIG. 3, memory 63 used upon executing pack separation and othersignal processes, video decoder (V decoder) 64 for decoding main picturedata (the contents of video packs) separated by separator 62,sub-picture decoder (SP decoder) 65 for decoding sub-picture data (thecontents of sub-picture packs) separated by separator 62, audio decoder(A decoder) 68 for decoding audio data (the contents of audio packs)separated by separator 62, video processor 66 for appropriately mixingsub-picture data from SP decoder 65 with video data output from Vdecoder 64 to superpose sub-picture data such as menus, highlightbuttons, superimposed dialogs, and the like on main picture data, andoutputting them, video digital-to-analog converter (V.DAC) 67 forconverting the digital video output from video processor 66 into ananalog video signal, and audio digital-to-analog converter (A.DAC) 69for converting the digital audio output from A decoder 68 into an analogaudio signal.

The analog video signal output from V.DAC 67 and the analog audio signaloutput from A.DAC 69 are supplied to an external component (not shown; amulti-channel stereo system having two to six channels+monitor TV orprojector) via AV output section 46.

OSD data output from MPU 30 is input to video processor 66 in decoderunit 60. The OSD data is superimposed on main picture data, and they aresupplied to an external monitor TV connected to AV output section 46.Thus, various kinds of text information are displayed together with mainpicture data.

The data processes in the RTR video recorder are roughly categorizedinto two processes, i.e., a recording process and playback process.

FIG. 30 is a flow chart for explaining an example of the recordingoperation in the RTR video recorder shown in FIG. 29.

Upon receiving an image recording command input by remote controlleroperation of the user or a timer recording program (not shown), MPU 30reads management data (file system and the like) from disc 10 (FIG. 1)set in disc drive 32 (step ST10), and determines the recording area(write area).

If disc 10 has no unrecorded area with a minimum required size or anarea that can be erased by overwriting data, i.e., if no free spaceexists (NO in step ST12), MPU 30 displays an alert message “no space isavailable for recording” (step ST14), thus stopping recording.

If a free space exists (YES in step ST12), MPU 30 determines a writeaddress (step ST16), and writes data required for recording (writing) onthe determined area in the management area (RTR_VMG file and the like)(step ST18).

MPU 30 then executes an initial setting process for recording (stepST20). More specifically, MPU 30 sets the average transfer rate (e.g., 4Mbps) in the respective encoders in encoder unit 50 shown in FIG. 29,resets STC 38 to a predetermined value (e.g., zero), sets a write startaddress in drive 32, initializes formatter 56 (e.g., for NTSC recordingbased on MPEG2/4 Mbps), enters dummy packs (FIGS. 3 and 4), sets thesegmentation time of cells to be a predetermined value, and sets thenumber C_EPI_Ns (FIG. 24) of pieces of cell entry point information tozero.

Upon completion of the aforementioned initial setting process, MPU 30sets a recording start command in the respective encoders in encoderunit 50 to start recording (step ST22), and starts a record process(step ST23).

The flow of a video signal in the record process (step ST23) is asfollows.

An AV signal input to external AV input section 42 or a broadcast signalreceived by TV tuner 44 are A/D-converted by ADC 52. The A/D-converteddigital video signal is input to V encoder 53, and the digital audiosignal is input to A encoder 54. Also, a closed caption signal or textsignal such as teletext or the like contained in the broadcast signal isinput from TV tuner 44 to SP encoder 55.

The respective encoders compress the input signals by a predeterminedmethod and packetize them to have 2,048 bytes per pack, and inputpackets to formatter 56.

Note that the respective encoders determine PTS (presentation time stampor playback time stamp) and DTS (decoding time stamp) of each packet inaccordance with the count value from STC 38, as needed, upon recording.

Formatter 56 temporarily stores packet data in buffer memory 57, thenpacks the input packet data, mixes them in units of GOPs, and transfersthe packs to data processor 36.

Data processor 36 forms groups of 16 transferred packs (2 kbytes),executes an ECC process of these packs using, e.g., a product code, andsends them to disc drive 32.

At this time, when disc drive 32 is not ready to record, data processor36 transfers the recording signal to the temporary storage buffer, andwaits until disc drive 32 is ready to record data. When disc drive 32 isready to record data, drive 32 starts recording.

In this case, a large-size memory is used as temporary storage buffer 34so as to store recording data for several minutes or more by high-speedaccess.

During the record process, a process for automatically entering entrypoints at prescribed time intervals (e.g., at 5-sec intervals) is done(step ST25; see FIG. 33). The user can arbitrarily set this entry pointentering time interval in units of minutes. If this time interval is setto be longer than the free space (recordable time) of disc 10, no entrypoints are automatically entered.

During recording (NO in step ST27), if the user requires entering of anentry point (YES in step ST29), a process for entering an entry point isdone (step ST31; see FIG. 31) independently of the process in step ST25.

For example, when a remote controller (not shown) has an entry pointkey, and the user has pressed this entry point key during the recordprocess, entry point information (FIG. 25) is entered at a positioncorresponding to the recorded contents at that time.

At this time, MPU 30 records entry point information in managementinformation (RTR_VMG file in FIG. 5) in response to the entry pointenter request from the user or set (RTR video recorder).

Upon completion of recording (YES in step ST27), MPU 30 initializes therespective encoders and formatter in encoder unit 50, sendspredetermined management information to drive 32, and records it inRTR_VMGI of disc 10 (step ST34).

FIG. 31 is a flow chart for explaining an example of the playbackoperation in the RTR video recorder shown in FIG. 29.

Upon receiving a playback command input by remote controller operationby the user or a timer playback program (not shown), MPU 30 reads thecontents of the management area (RTR_VMG) of disc 10 via drive 32 anddata processor 26 (step ST40), and determines the playback address.

MPU 30 selects a program chain and programs to be played back on thebasis of the read management data (step ST42), and sets a playback startcommand in the respective decoders in decoder unit 60 (step ST44).

MPU 30 then sends the determined playback address and read command todrive 32 and starts a playback process (step ST46).

Drive 32 reads out sector data of disc 10 (FIG. 1) in accordance withthe received read command, and data processor 36 corrects errors ofreadout data, and outputs the data to decoder unit 60 in the form ofpack data.

In decoder unit 60, separator 62 receives the readout pack data.Separator 62 packetizes the received data, and transfers packets inaccordance with the types of data (video data, audio data, sub-picturedata, and the like). That is, separator 62 transfers video packet data(MPEG video data) to v decoder 64, audio packet data to A decoder 68,and sub-picture data to SP decoder 65.

At the beginning of transfer of packet data to the respective decoder,SCR (system clock reference or reference system clock) data is loadedonto STC 38. The respective decoders execute playback processes insynchronism with PTS values (see FIG. 3) in packet data (that is, bycomparing PTS and STC values). In this manner, a moving picture withaudio and superimposed dialog data, which are synchronous with a video,can be played back.

If playback from an entry point of a specific cell is required duringplayback (YES in step ST50), MPU 30 converts EP_PTM (see FIG. 25) of thetarget entry point into a file pointer with reference to TMAP (see FIG.14), and accesses a VOBU (see FIG. 28) corresponding to that entry point(step ST52).

If playback from an entry point is not required (NO in step ST50), theplayback process continues.

If enter of an entry point is required during the playback process (YESin step ST54), a process for entering an entry point can be executed(step ST31). This entry point enter process can have the same contentsas that (ST31 in FIG. 30) upon recording.

If playback is to end (YES in step ST48), MPU 30 waits for completion ofplayback of the VOBU, playback of which is in progress at that time, andthen sets the respective decoders in decoder unit 60 upon stoppingdecoding (step ST58), thus ending the playback process.

FIG. 32 is a flow chart for explaining an example of a process executedwhen recording or playback of the RTR video recorder (recorder/player)is underway, and the user or recorder/player requests enter of an entrypoint with respect to specific video or audio data. This entry pointenter process corresponds to step ST31 in FIG. 30 or 31.

Upon receiving the entry point enter request from the user orrecorder/player (step ST310), MPU 30 of the RTR video recorder(recorder/player) shown in FIG. 29 increments C_EPI_Ns (FIG. 24) inmovie cell general information M_C_GI by “1” (step ST312).

If no entry point enter request is input, C_EPI_Ns is set at “0”.

Incrementing C_EPI_Ns by “1” means addition of one entry pointinformation in a cell of a program whose recording (or playback) isunderway. Hence, MPU 30 assures an area for movie cell entry pointinformation (M_C_EPI) in movie cell information (M_CI).

Assume that the user has made a text input or the recorder/player hasgiven closed caption data or the like of a broadcast program, air-checkof which is underway, as a text input within a predetermined period oftime (e.g., within 30 sec) after that (YES in step ST314).

Note that the text input is not limited to a character input butincludes an operation result input when the user has selected a menuitem or has clicked a mouse button.

MPU 30 sets “1” in entry point type EP_TY in movie cell entry pointinformation M_C_EPI (step S316). EP_TY=“1” indicates that M_C_EPIincludes primary text information PRM TXTI.

Subsequently, MPU 30 reads the current count value of STC 38 and writesthe read value in entry point playback time EP_PTM (FIG. 25) in M_C_EPI(step ST320).

Furthermore, MPU 30 reads the current time (year, month, day, hour,minute, and second) from timepiece unit 40, and writes the read value inan information date (FIG. 25) in primary text information PRM_TXTI inM_C_EPI (step ST322).

After that, MPU 30 writes the following attribute data (one of 0 to 7)in information type [1] in primary text information PRM_TXTI (stepST324):

information type [1]=0, user mark (the user enters an entry point)

information type [1]=1; set mark (the recorder/player enters an entrypoint)

information type [1]=2; defect start mark

information type [1]=3; defect end mark

information type [1]=4; presentation start mark

information type [1]=5; presentation end mark

information type [1]=6; erasure prohibition mark

information type [1]=7; another mark (e.g., an instruction from otherthan the user or recorder/player).

Note that [1] in information type [1] means the first data field of theinformation type. If this data field has a 3-bit configuration,information type [1] can express eight different attributes; if it hasan 8-bit configuration, 256 different attributes.

More specifically, when the user requests enter of an entry point,information type [1]=0; when the recorder/player, i.e., the RTR videorecorder set requests enter of an entry point, information type [1]=1.

Information type [1]=2 is set for a defect start mark (to be describedlater), and information type [1]=3 is set for a defect end mark.

Also, information type [1]=4 is set for a presentation start mark (to bedescribed later), and information type [1]=5 is set for a presentationend mark.

Information type [1]=6 is set for an erasure prohibition mark (to bedescribed later).

Furthermore, information type [1]=7 is set when the entry point enterrequest is sent from a broadcast station during recording of a broadcastprogram or is sent from a communication partner during downloading ofdigital video data via a communication line.

If no text input is made for the entry point in the entry point enterprocess (NO in step ST314), “0” is set in EP_TY (step ST318).

MPU 30 sets “0” in EP_TY in movie cell entry point information M_C_EPI(step ST316). EP_TY =“0” indicates that primary text informationPRM_TXTI in M_C_EPI is empty.

In this case, MPU 30 sets PTS in EP_PTM (step ST330), and setspredetermined contents in information type [1] in PRM_TXTI (step ST324),thus ending the entry point enter process.

FIG. 33 is a flow chart for explaining an example of an automatic entrypoint enter process (for entering entry points at given time intervals)in the RTR video recorder shown in FIG. 29.

In this process, entry points are automatically entered at prescribedtime intervals (without interrupting recording) irrespective of thecontents of video picture or audio data to be recorded.

Before the start of recording, the user executes an initial settingprocess. That is, the user sets a numerical value of parameter a whichdesignates the entry point enter interval in units of minutes, and indexparameter n is preset to “1” (step ST200).

If the user does nothing, a predetermined default value (for example,a=5 indicating 5-min intervals, a=0 that prohibits entry points frombeing automatically entered, or the like) is selected, and n is presetto “1”.

If recording is started after the initial setting process at the startof recording, the process for entering entry points at prescribedintervals is executed at, e.g., the timing of step ST25 in FIG. 30.

That is, STC indicating an elapse of recording time is compared with a(n(5400000 (corresponding to an minutes when 90-kHz clocks are used)(step ST250).

If an minutes (initially, an=5 min) have not elapsed yet after the startof recording (NO in step ST250), the control returns to the recordprocess in step ST23 in FIG. 30.

If an minutes (an=5 min) have elapsed after the start of recording (YESin step ST250), the entry point enter process with the contents thathave been explained with reference to, e.g., FIG. 32 is executed (stepST31).

If the entry point at that time (when 5 minutes have elapsed after thestart of recording) has been entered, index parameter n is incrementedby “1” (step ST252), and the control returns to the record process instep ST23 in FIG. 30.

If an minutes (next, an=10 min) have not elapsed yet after the start ofrecording (NO in step ST250), the control returns to the record processin step ST23 in FIG. 30.

If an minutes (an=10 min) have elapsed after the start of recording (YESin step ST250), the entry point enter process with the contents thathave been explained with reference to, e.g., FIG. 32 is executed (stepST31).

The aforementioned processes are repeated until recording is completed.As a result, when a television broadcast program for 54 min is recorded,10 entry points are automatically recorded at 5-min intervals.

Note that the RTR video recorder automatically enters entry points atthe start of recording, at the end of recording, at the pause ofrecording, at the start of playback, at the end of playback, at thepause of playback, upon switching video picture data to be recorded,upon switching video audio data to be recorded, and so forth, inaddition to the aforementioned process for entering entry points atgiven time intervals irrespective of recorded contents.

For example, whether or not the audio level of the recording source haschanged (whether or not a predetermined audio level or lower continuesfor a predetermined period of time) is detected, and an entry point canbe automatically entered at that detection position.

Alternatively, a scene change is detected from a change in MPEG videodata in the recording source (when the image contents have changeddrastically due to a scene change, since the moving picture compressionratio lowers, the buffer capacity in an MPEG encoder is consumedabruptly within a short period of time), and an entry point can beautomatically entered at that detection position.

FIG. 34 is a flow chart for explaining an example of the textinformation input process in the RTR video recorder shown in FIG. 29.

MPU 30 reads management data (RTR_VMG and the like in FIGS. 5 and 6)from disc 10 (step ST100). As a result of reading this data, MPU 30 candetect the play list information contents (FIGS. 8 to 11), PGCinformation contents (FIGS. 19 to 21), and contents of movie cellinformation M_CI (FIGS. 23 to 25), as needed.

MPU 30 reads the contents of movie cell entry point information M_C_EPIof all the entry points from the read management data (step ST102).

More specifically, MPU 30 selectively extracts entry points with entrypoint type EP_TY =“01b” (with primary text information PRM_TXTI) fromM_C_EPI (FIG. 25) of the individual entry points. Then, MPU 30 readsentry point playback time EP_PTM and primary text information PRM_TXTIfrom the entry point information with PRM_TXTI. Furthermore, MPU 30reads the information type, information date, and text information ofthat entry point from read PRM_TXTI.

This M_C_EPI read process is repeated if unprocessed entry points stillremain (NO in step ST104).

If all entry points have undergone the M_C_EPI read process (YES in stepST104), MPU 30 outputs input menu information to the monitor on thebasis of the read contents (step ST106).

In this input menu, for example, as shown in FIG. 35, playback times(hour, minute) based on EP_PTM, titles based on text information inPRM_TXTI, thumbnail images based on THM_PTRI (FIG. 10), attributes basedon the information types in PRM_TXTI, and mark recording dates (year,month, day, hour, minute, and second) based on the information dates inPRM_TXTI are displayed while being categorized in units of items and aresorted in the order of playback times (or recording times).

The user moves the cursor to a predetermined line position of a titlefield in the menu using the cursor keys of a remote controller (notshown), an optional keyboard, or the like, and selects an entry point orpoints which is or are to undergo text input (step ST108). In thismanner, the user can input desired text to a target entry point orpoints by operating the remote controller or keyboard (step ST110).

The aforementioned text input is done for all the entry points the userwants (YES in step ST112, ST106 to ST110).

If the text input is complete for all the entry points the user wants(NO in step ST112), text information (FIG. 25) in PRM_TXTI of M_C_EPI isupdated to the contents exemplified in FIG. 35 (step ST114), and theupdated data is written in a predetermined area of the management data(RTR_VMG) (step ST116).

In this fashion, the user inputs his or her desired text information orthe like to an entry point or points he or she wants, and the inputcontents are entered in disc 10 (FIG. 1).

FIG. 36 depicts a state wherein information exemplified in FIG. 35 hasbeen entered in disc 10 by the processes shown in FIG. 34.

Referring to FIG. 36, attribute “10” of an entry point at the start ofrecording (recording time 00′00″) and attribute “10” of an entry pointat the end of recording (recording time 02′00″) indicate that the RTRvideo recorder has automatically entered entry points. Note that therecording date is written on the basis of time data from timepiece unit40 in FIG. 29, and text “Cinderella” is extracted from closed captiondata at the beginning of a broadcast program (broadcast with text) andis automatically written.

Entry points at three positions of recording times 00′30″, 01′00″, and01′10″of the disc indicate overwritten recorded portions in the middleof the recorded program “Cinderella” by user operations. For thisreason, the attributes of these entry points are “00” indicating theuser mark, and their recording dates are largely different from that of“Cinderella”.

At each entry point entered by the user, an image (obtained by reducingthe I-picture of MPEG) at that position is extracted as a thumbnail,which is entered in THM_PTRI of play list search pointer PL_SRP (FIG.10) as one entry point data.

FIG. 37 exemplifies a case wherein the user inputs text at each entrypoint in place of the thumbnails entered, as shown in FIG. 36, and textinformation is entered in PRM_TXTI (FIG. 25) of movie cell entry pointinformation M_C_EPI.

FIG. 38 is a flow chart for explaining an example of the playback menudisplay process in the RTR video recorder shown in FIG. 29.

MPU 30 reads management data (RTR_VMG and the like) from disc 10 (stepST700). As a result of reading this data, MPU 30 can detect the playlist information contents (FIGS. 8 to 11), PGC information contents(FIGS. 19 to 21), and contents of movie cell information M_CI (FIGS. 23to 25), as needed.

MPU 30 reads the contents of movie cell entry point information M_C_EPIof all the entry points from the read management data (step ST702).

More specifically, MPU 30 selectively extracts entry points with entrypoint type EP_TY=“01b” (with primary text information PRM TXTI) fromM_C_EPI (FIG. 25) of the individual entry points. Then, MPU 30 readsprimary text information PRM_TXTI, and information [1] of that entrypoint.

The description contents of this information type [1] are:

information type [1]=0, user mark (the user enters an entry point)

information type [1]=1; set mark (the recorder/player enters an entrypoint)

information type [1]=2; defect start mark

information type [1]=3; defect end mark

information type [1]=4; presentation start mark

information type [1]=5; presentation end mark

information type [1]=6; erasure prohibition mark

information type [1]=7; another mark (e.g., an instruction from otherthan the user or recorder/player).

If read information type [1] is “0” (user mark) or “1” (set mark) (YESin step ST703), MPU 30 further reads the information date and textinformation from primary text information PRM_TXTI (step ST704).

If read information type [1] is neither “0” nor “1” (NO in step ST703),the control skips step ST704.

The M_C_EPI information read process (ST702 to ST704) is repeated ifunprocessed entry points still remain (NO in step ST706).

By repeating this process, MPU 30 can fetch all pieces of movie cellinformation at entry points of the user marks or set marks.

If all entry points have undergone the M_C_EPI read process (YES in stepST706), MPU 30 outputs playback menu information to the monitor on thebasis of the read contents (step ST708).

In this playback menu, for example, as shown in FIG. 39, playback times(hour, minute) based on EP_PTM, titles based on text information inPRM_TXTI, thumbnail images based on THM_PTRI (FIG. 10), attributes basedon the information types in PRM_TXTI, and mark recording dates (year,month, day, hour, minute, and second) based on the information dates inPRM_TXTI are displayed while being categorized in units of items and aresorted in the order of playback times (or recording times).

The user moves a title select cursor to a desired line position in theplayback menu by operating the cursor keys of a remote controller (notshown) and selects an entry point to be played back (step ST710).

MPU 30 converts the entry point playback time value of the selectedentry point into a corresponding file pointer on the basis of time mapinformation (FIGS. 14 to 16) (step ST712). Using this file pointer, theentry point playback time value is converted into a physical address(VOBU address) by the file system, thus starting playback.

FIG. 40 is a flow chart for explaining an example of the textinformation search process in the RTR video recorder shown in FIG. 29.

MPU 30 executes a process for displaying the playback menu used to inputa search keyword (step ST400).

This playback menu for search is used when the user inputs a keywordupon searching information recorded in M_C_EPI (FIG. 25) of respectiveentry points.

For example, assume that the user inputs search keywords to search forall entry points which include a character string “Cinderella” in theirtitles and were marked on January 1999 (step ST402), as shown in FIG.41.

MPU 30 reads management data (RTR_VMG) from disc 10, and acquires thecontents of movie cell information M_CI of all the recorded entry points(step ST404).

MPU 30 then extracts M_C_EPI from the acquired information, and readsthe information date and text information from PRM_TXTI (FIG. 25) inthat information (step ST406).

MPU 30 searches based on the keywords (to search for entry points whichinclude a character string “Cinderella” and were marked on January 1999)set by the user.

As a result, if an entry point that is a match to the keywords is found(YES in step ST408), MPU 30 reads information type [1] of that entrypoint from PRM_TXTI of the entry point (step ST410).

The description contents of this information type [1] are:

information type [1]=0, user mark (the user enters an entry point)

information type [1]=1; set mark (the recorder/player enters an entrypoint)

information type [1]=2; defect start mark

information type [1]=3; defect end mark

information type [1]=4; presentation start mark

information type [1]=5; presentation end mark

information type [1]=6; erasure prohibition mark

information type [1]=7; another mark (e.g., an instruction from otherthan the user or recorder/player).

Based on the contents of read information type [1], entry points withinformation type [1] other than “1” can be excluded from the searchresults, and only entry points written by the RTR video recorder uponrecording can be left as search results.

Alternatively, if read information type [1] is “2” (or 2X; X is anarbitrary integer value) or 3 (or 3X), a defect (e.g., ECC errorcorrection failure upon playback or the like) is present at therecording position of the cell corresponding to that entry point, andsuch entry point can be excluded from search results in some cases.

If the search is complete and no entry point to be searched remains (YESin step ST412), MPU 30 displays the search results on the monitor, asshown in, e.g., FIG. 42 (step ST414).

MPU 30 converts the entry point playback time value of each entry pointfound by search into a corresponding file pointer on the basis of timemap information (in FIGS. 14 to 16) (step ST418). Using this filepointer, the entry point playback time value can be converted into aphysical address (VOBU address) by the file system, and only an entrypoint mark portion found by search can be selectively played back.

FIG. 43 is a flow chart for explaining an example of the defect enterprocess in the RTR video recorder shown in FIG. 29.

This defect enter process is executed, for example, when the user wantsto check an old disc.

MPU 30 reads management data (RTR_VMG) (step ST500), and resets a defectflag to “0” (step ST502).

This defect flag can be set in a given field of the internal RAM orregister of MPU 30.

Then, MPU 30 plays back disc 10 (step ST504). This playback process isthe same as that in step ST46 in FIG. 31.

Initially, the defect flag is “0” (YES in step ST506). During playback,if no defect (ECC error correction failure) is found (NO in step ST508),and playback is not terminated (NO in step ST516), playback is normallycontinued (loop of steps ST504 to ST516).

If any defect (ECC error correction failure) is found during playback(YES in step ST508), MPU 30 increments the number C_EPI_Ns (FIG. 24) ofpieces of cell entry point information by “1”, sets “1” in entry pointtype EP_TY (FIG. 25), sets PTS (FIG. 3) at that time in entry pointplayback time EP_PTM (FIG. 25), and sets current date (date data fromtimepiece unit 40) in the information date (FIG. 25) in primary textinformation PRM_TXTI (step ST510).

Then, MPU 30 sets 2X (X is an arbitrary integer value) in theinformation type in primary text information PRM_TXTI (step S512). Withthis information type set with 2X, the defect start point is entered.

If a defect is found for the first type, 2X of information type is setto be “20”. If the second defect is found, 2X=21; if the third defect isfound, 2X=22.

Upon completion of entering of the defect start points, MPU 30 sets thedefect flag at “1” (step ST514).

If playback is not terminated (NO In step S516), playback continues(step ST504).

Since the defect flag is set at “1” immediately before continuation ofplayback (NO in step ST506), the control enters another processing loopin turn.

The presence/absence of defects (the presence/absence of ECC errorcorrection failures) is checked. If a defect still continues to bedetected (YES in step ST518), and playback is not terminated (NO in stepS526), MPU 30 transfers data that informs the user that playback of adefective portion is in progress to video decoder 64. Then, alertcharacters or mark “playback of defective portion now in progress” aredisplayed on the blue back on the monitor screen (not shown) (stepST528). Alternatively, if I-picture data (free from any defect)immediately before the defect flag is set at “1” remains on a videobuffer (not shown) of decoder unit 60, that I-picture data may betransferred to video decoder 64 for the purpose of informing the userthat playback of a defective portion is in progress.

If the defect disappears after the defect flag is set at “1” (ECC errorcorrection has succeeded), that position corresponds to the end point ofthe defective portion.

If playback of the defective portion comes to an end, and ECC errorcorrection recovers normal function (NO in step ST518), MPU 30increments the number C_EPI_Ns (FIG. 24) of pieces of cell entry pointinformation by “1”, sets “1” in entry point type EP_TY (FIG. 25), setsPTS (FIG. 3) at that time in entry point playback time EP_PTM (FIG. 25),and sets current date (date data from timepiece unit 40) in theinformation date (FIG. 25) in primary text information PRM_TXTI (stepST520).

MPU 30 then sets 3X (X is an arbitrary integer value) in the informationtype (FIG. 25) in primary text information PRM_TXTI (step ST522). Withthe information type set with 3X, the defect end point is entered.

If a defect is found for the first type, 3X of information type is setto be “30”. If the second defect is found, 3X=31; if the third defect isfound, 3X=33.

Note that 2X (20, 21, 22, . . . ) in step S512 is paired with 3x (30,31, 32, . . . ) in step ST522. More specifically, a pair of informationtypes “20” and “30” are assigned to the first defect as those of theentry points of the defect start and end points.

Upon completion of entering of the defect end point, MPU 30 resets thedefect flag to “0” (step ST524).

After that, if playback is not terminated (NO in step S526), playbackcontinues (step ST504).

Since the defect flag is “0” in this case, the loop of steps ST504 toST516 is executed until a new defective portion begins to be playedback.

If playback is terminated without any defects (NO in step ST508, YES instep ST516), no information type=2X is entered, and only an informationtype=3X is entered (step ST522). In this case, entry points do not formany pairs mentioned above. This record shows that no defect is foundduring playback of the disc.

FIG. 44 shows an example of entry points when two defects are found bythe process shown in FIG. 43.

If the defect positions of the disc of interest can be detectedbeforehand based on pairs of information types (contents of PRM_TXTI inFIG. 25) entered in steps ST512 and ST522 in FIG. 43, how to play backsuch defective portions can also be determined. Hence, a menu thatprompts the user to select a defective portion reproduction manner isneeded. FIG. 45 shows an example of such defect management menu.

More specifically, even when the disc of interest has a defect, andsuffers many MPEG block noise components (or digital audio data isdistorted and sometimes discontinued), if the user wants to play back toconfirm the contents of that portion, he or she can select areproduction manner “incomplete video playback”.

When a defect is disagreeable to see, the user can select a reproductionmanner “skip that portion, and display alert on blue back on monitor”.

Alternatively, in place of alert display on the blue back, the user mayselect a reproduction manner “display alert while displaying still imageof I-picture immediately before error has occurred as background image”.

The data that pertain to the reproduction manners can be enteredanywhere (e.g., as a kind of information type) in M_C_EPI in FIG. 25.

FIG. 46 is a flow chart for explaining an example of the process forentering the priority order of erasure in the RTR video recorder shownin FIG. 29.

MPU 30 reads management data (RTR_VMG and the like) from disc 10 (stepST600). As a result of reading this data, MPU 30 can detect the playlist information contents (FIGS. 8 to 11), PGC information contents(FIGS. 19 to 21), and contents of movie cell information M_CI (FIGS. 23to 25), as needed.

MPU 30 reads the contents of movie cell entry point information M_C_EPIof all the entry points from the read management data (step ST602).

More specifically, MPU 30 selectively extracts entry points with entrypoint type EP_TY=“01b” (with primary text information PRM_TXTI) fromM_C_EPI (FIG. 25) of the individual entry points. Then, MPU 30 readsprimary text information PRM_TXTI, and information [1] of that entrypoint.

The description contents of this information type [1] are:

information type [1]=0, user mark (the user enters an entry point)

information type [1]=1; set mark (the recorder/player enters an entrypoint)

information type [1]=2; defect start mark

information type [1]=3; defect end mark

information type [1]=4; presentation start mark

information type [1]=5; presentation end mark

information type [1]=6; erasure prohibition mark

information type [1]=7; another mark (e.g., an instruction from otherthan the user or recorder/player).

If read information type [1] is “4” (presentation start mark) or “6”(erasure prohibition mark) (YES in step ST603), MPU 30 further reads theinformation date and text information from primary text informationPRM_TXTI (step ST604).

If read information type [1] is neither “4” nor “6” (NO in step ST603),the control skips step ST604.

The M_C_EPI information read process (ST602 to ST604) is repeated ifunprocessed entry points still remain (NO in step ST606).

By repeating this process, MPU 30 can fetch all pieces of movie cellinformation at entry points of the presentation start marks or erasureprohibition marks.

If all entry points have undergone the M_C_EPI read process (YES in stepST606), MPU 30 outputs erasure (or delete) menu information to themonitor on the basis of the read contents (step ST608).

In this erasure menu, for example, as shown in FIG. 48, playback times(hour, minute) based on EP_PTM, titles based on text information inPRM_TXTI, thumbnail images based on THM_PTRI (FIG. 10), attributes basedon the information types in PRM_TXTI, playback dates (year, month, day,hour, minute, and second) based on the information dates in PRM_TXTI,and the erasure order (or erasure prohibition marks) based oninformation type [0] of PRM_TXTI are displayed while being categorizedin units of items and are sorted in the order of playback times (orrecording times).

Note that a pair of information type [0]=4X (erasure start point) andinformation type [0]=5X (erasure end point) are set as information type[0], as exemplified in the attribute fields of entry points in FIG. 47.

In information type [0], identical values are written in turn from “0”in pairs of movie cell information, but the same value as that ofanother pair of movie cell information must not be written.

For example, in FIG. 47, a recorded video (recording time=15 min from00′30″ to 00′45″) with a title “peace”, which has a pair of entry pointattributes (information type [0]) “40” and “50” has the first erasureorder on the erasure menu in FIG. 48, if the remaining size of the discbecomes short during recording, this recorded video with the title“peace” is erased at the very beginning by overwriting another data.

The user moves the cursor to a predetermined position of an erasureorder field in the menu in FIG. 48 using the cursor keys of a remotecontroller (not shown), an optional keyboard, or the like, and selectsentry points, the erasure order of which is to be changed.

If the user wants to set a lower erasure order of a cell correspondingto the selected entry points (YES in step ST610), he or she decreasesthe order of information type [0] of each entry point to be changed by“1” (for both entry points with information type [1]=4 and informationtype [1]=5) (for example, to change the erasure order from the second tothe third) (step ST612).

Conversely, if the user wants to set a higher erasure order, he or sheincreases the order of information type [0] of each entry point to bechanged by “1” (for both entry points with information type [1]=4 andinformation type [1]=5) (for example, to change the erasure order fromthe second to the first) (step ST612).

If the erasure order is not to be changed (NO in step ST610), anderasure is to be prohibited (YES in step ST614), information type [1] ofthat entry point is set at “6” (erasure prohibition mark) (step ST616).

Upon completion of the erasure order change or erasure prohibition markset process (YES in step ST618), management data (RTR_VMG) written withinformation corresponding to PRM_TXTI shown in FIG. 25 is written indisc 10 (step ST620).

If the remaining size of disc 10 becomes short during recording, MPU 30can proceed with recording while erasing some data on disc 10 byoverwriting in units of entry points in the erasure order (or inascending order of recording dates or playback dates if no erasure orderis set).

FIG. 49 shows a stream pack structure used when a streamer is used forthe DVD-RTR recorder. As shown in the figure, one stream pack (2048bytes) is formed of a pack header (14 bytes) and a stream PES packet(2034 bytes).

The pack header of the stream pack has 14 bytes in size. In this packheader, a pack start code is described in the first 4 bytes (00001Bah).In the next 6 bytes, reference information of system clock reference SCR(SCR base with 32 bits total) defined by a provider, marker bits, andextension of system clock reference (SCR_extension with 9 bits) aredescribed. In the subsequent 3 bytes (0189C3h), a program multiplexedrate (program_mux_rate with 22 bits) and marker bits are described. Inthe last 1 byte (Fb 8h), a pack stuffing length (pack stuffing lengthwith 3 bits) is described, and a reserved area of 5 bits is furtherprovided.

The 32nd bit of SCR_base is set to zero. The program_mux_rate is set to10.08 Mbps.

In stream recording, an application performs its own stuffing, so thatthe pack length adjustment methods of DVD-VIDEO or DVD-VR (DVD videorecording) need not be used. In stream recording, it is safe to assumethat the stream packs will always have the necessary length.

A stream PES packet of the stream pack has the following data structure.

FIG. 50 illustrates a structure of the stream data area contained in thestream PES packet shown in FIG. 49.

As shown, one stream PES packet (2034 bytes) includes a PES header (6bytes), a substream ID (1 byte), and a stream data area (2027 bytes).

In the PES packet header of the stream PES packet, a packet start codeprefix (packet_start_code_prefix with 24 bits) is recorded at the first3 bytes (000001h). In the next 1 byte, a stream ID (stream_id=101111b;indicating private stream 2) is recorded. In the subsequent 2 bytes(07Ech), a PES packet length (PES_packet_length with 16 bits) isrecorded, In the last 1 byte, a substream ID (sub stream_id=00000010b;indicating stream recording data) is recorded.

The stream data area (2027 bytes) within the stream packet of FIG. 50includes an application header (9 bytes), an application headerextension (optional), a stuffing byte (optional), and an applicationpacket area.

The application packet area of FIG. 50 contains one or more applicationpackets each of which is associated with an application time stamp.

At the leading portion of the application packet area, a partialapplication packet can be recorded. Thereafter, a plurality of pairs ofapplication time stamp ATS and application packet are sequentiallyrecorded. At the trailing portion of the application packet area,another partial application packet can be recorded.

In other words, at the start of the application packet area, a partialapplication packet may exist, and at the end of the application packetarea, another partial application packet or a stuffing area of reservedbytes may exist.

The application time stamp (ATS) arranged in front of each applicationpacket has 32 bits in size. An ATS can be divided into two parts, namelya base part and an extension part. The base part holds a 90 kHz unitvalue, and the extension part holds the less significant value measuredin 27 MHz.

In the structure of FIG. 50, the application header extension may beused to store information that can differ from application packet toapplication packet. Such information may not be required for all kindsof applications.

Therefore, a data field of the application header is defined to describethe presence of the optional application header extension in the streamdata area.

At stream recording, the first byte of application time stamp ATS of thefirst application packet should be aligned to the start of theapplication packet area in the first stream packet at the beginning of astream object (SOB).

Any following stream packets in an SOB may split application packetsacross stream packet boundaries. The partial application packets in FIG.50 show examples obtained by the above splitting.

The byte offset to the first application time stamp that starts in astream packet, as well as the number of application packets starting inthe stream packet, should be described in its application header.

This mechanism automatically allows for stuffing in front of the firstapplication time stamp and after the last application packet in a streampacket.

The above automatic mechanism corresponds to said “an applicationperforms its own stuffing” mentioned in the description for FIG. 49.

The application header extension (optional) is formed of a list ofentries, where there is exactly one entry of 1 byte length for eachapplication packet, which starts in this stream packet. These bytes canbe used to store information that may differ from application packet toapplication packet.

In the 1 byte application header extension (optional), 1 bit AU_START, 1bit AU_END, and 2 bits COPYRIGHT are described.

When AU_START is set to “1”, this indicates that the associatedapplication packet contains a random access entry point (start of arandom access unit) in the stream.

When AU_END is set to “1”, this indicates that the associatedapplication packet is the last packet of a random access unit.

The COPYRIGHT describes the copyright status of the associatedapplication packet.

FIG. 51 shows entry point relating information with respect to moviecell information M_CI contained in PGCI of the RTR video manager.

More specifically, movie cell general information M_C_GI contained inM_CI includes the number of cell entry point information C_EPI_Ns (cf.FIG. 24), and movie cell entry point information M_C_EPI contained inM_CI includes entry point type EP_TY, entry point presentation timeEP_PTM and primary text information PRM_TXTI (cf. FIG. 25). In thisPRM_TXTI, the information type, information date and text informationcan be described.

FIG. 52 shows entry point relating information with respect to stillpicture cell information S_CI contained in PGCI of the RTR videomanager.

More specifically, still picture cell general information S_C_GIcontained in S_CI includes the number of cell entry point informationC_EPI_Ns, and still picture cell entry point information S_C_EPIcontained in S_CI includes entry point type EP_TY, still picture VOBentry number S_VOB_ENTN and primary text information PRM_TXTI. In thisPRM_TXTI, the information type, information date and text informationcan be described.

FIG. 53 shows entry point relating information with respect to streamcell information SCI contained in PGCI of the RTR stream manager.

More specifically, stream cell information general information SCI_GIcontained in SCI includes the number of stream cell entry pointinformation SC_EPI_Ns, and stream cell entry point information SC_EPIcontained in SCI includes entry point type EP_TY, application packetarrival time of entry point EP_APAT and primary text informationPRM_TXTI. In this PRM_TXTI, the information type, information date andtext information can be described.

According to the embodiment (real-time digital video recording/playbacksystem) of the present invention, the user can write or erase a mark(entry point) at an arbitrary recording position of video data, audiodata, and the like as if he or she placed a bookmark between pages or atan important position while reading a book.

When information that pertains to the mark (entry point) is recorded ata predetermined position (movie cell entry point information or thelike) on a medium (disc), the user can enjoy the following merits usingthis information upon playing back or recording (including overwrite anderasure).

1) An index that indicates programs and their recording positions on adisc can be freely generated.

That is, when that disc is set in the apparatus, the user can easilyknow the recorded contents of marked portions (entry points), and canstart to play back such portions by simple operation.

2) A desired program can be easily found by searching various programrecorded on a disc.

That is, when that disc is set in the apparatus (RTR video recorder),the user can search for titles of the marked portions (entry points)using a keyword. As a result of search, the user can easily know only adesired program of various ones recorded on the disc, and can start toplay back that portion by simple operation.

3) A portion that can be erased (by overwrite recording) (or a portionthat is not to be erased) of various programs recorded on a disc can beeasily specified.

That is, when that disc is set in the apparatus, the user can easilyknow the priority order of erasure or erasure permission/prohibition ofthe marked portions (entry points), and can change the priority order oferasure or erasure permission/prohibition of a desired portion by simpleoperation. A program corresponding to a marked portion which is notprohibited from being erased is automatically erased by overwriting inaccordance with the priority order of erasure upon recording new data onthat disc.

4) When a portion of the recorded disc becomes defective, and cannot benormally played back, the defective portion that cannot be normallyplayed back can be easily specified.

More specifically, when that disc is set in the apparatus, the user caneasily know if the respective marked positions (entry points) sufferdefects. If any defect is found, the reproduction manner of that portion(skip a defective portion, display the blue back during playback of adefective portion, play back a still image immediately before a defectuntil a normal portion is played back, and so forth) can be arbitrarilydesignated.

As described above, according to the real-time digital videorecording/playback system of the present invention, even when the sizeof the disc to be recorded increases, the user can easily manage itscontents, and can start recording/playback from a position of his or herchoice.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. A data structure, comprising: a data areaconfigured to store data in a form of at least one object, and in whicheach object includes at least one object unit having record informationin a form of at least one pack; and a management area configured tostore management information for managing said at least one object, andin which said management information includes program chain informationconfigured to specify a manner of presentation of said at least oneobject, wherein said program chain information relates to at least onepiece of cell information, and wherein said cell information has an areaconfigured to describe entry point information of at least one entrypoint, each entry point marking an arbitrary position in said recordinformation for a user to freely set said record information.
 2. Thedata structure of claim 1, wherein said entry point information includesprimary text information.
 3. The data structure of claim 2, wherein saidprimary text information includes at least one of an information type,an information date and text information.
 4. The data structure of claim1, wherein said entry point information includes entry point typeinformation.
 5. The data structure of claim 1, wherein said cellinformation includes cell general information, and said cell generalinformation includes information indicating a number of pieces of theentry point information.
 6. The data structure of claim 1, wherein saidprogram chain information includes at least one piece of programinformation, and said program information includes primary textinformation.
 7. The data structure of claim 6, wherein said primary textinformation includes at least one of an information type, an informationdate and text information.
 8. The data structure of claim 1, whereinsaid record information includes video information, and said entry pointinformation includes presentation time information of an entry point ofsaid video information.
 9. The data structure of claim 1, wherein saidrecord information includes still picture information, and said entrypoint information includes number information of an entry point of saidstill picture information.
 10. The data structure of claim 1, whereinsaid record information includes audio information, and said entry pointinformation includes information of an entry point of said audioinformation.
 11. The data structure of claim 1, wherein said managementinformation includes a play list search pointer table, and said playlist search pointer table includes primary text information.
 12. Thedata structure of claim 11, wherein said primary text informationincludes at least one of an information type, an information date andtext information.
 13. The data structure of claim 1, wherein: said dataarea is configured to store bitstream data, said at least one packincludes a stream packet including said bitstream data, said streampacket includes at least one application packet associated with apredetermined time stamp, and said entry point information includesinformation of an arrival time of a respective application packet withsaid entry point, when said entry point is assigned to said at least oneapplication packet.
 14. The data structure of claim 13, wherein saidentry point information includes primary text information configured todescribe information relating to at least one selected entry point. 15.The data structure of claim 14, wherein said primary text informationincludes at least one of an information type, an information date andtext information.
 16. The data structure of claim 13, wherein said entrypoint information includes entry point type information.
 17. Aninformation medium, comprising: a data area configured to store data ina form of at least one object, and in which each object includes atleast one object unit having record information in a form of at leastone pack, said record information being presented within a prescribedperiod of time; and a management area configured to store managementinformation for managing said object, and in which said managementinformation includes program chain information configured to specify anorder of presentation of said at least one object, wherein said programchain information includes at least one piece of cell information, andwherein said cell information has an area configured to describeinformation of at least one entry point, each entry point marking anarbitrary position in said record information for a user to freely setsaid record information.
 18. The information medium of claim 17, whereinsaid medium comprises one of an optical disc and a semiconductor memorydevice.
 19. An information medium, comprising: a data area configured tostore at least one data object having record information; and amanagement area configured to store management information for managingsaid at least one data object, and in which said management informationincludes program chain information configured to specify a manner ofpresentation of said at least one data object, wherein said programchain information includes at least one piece of cell information, andwherein said cell information has an area configured to describe entrypoint information of at least one entry point, each entry point markingan arbitrary position in said record information for a user to freelyset contents of said at least one data object.
 20. The medium of claim19, wherein the contents of said at least one data object includes videoinformation, and said entry point information includes presentation timeinformation of an entry point of said video information.
 21. The mediumof claim 19 wherein the contents of said data objects includes stillpicture information, and said entry point information includes numberinformation of an entry point of said still picture information.
 22. Themedium of claim 19, wherein: said data area is configured to storebitstream data included in a stream packet, said stream packet includesat least one application packet associated with a predetermined timestamp, and said entry point information includes information of anarrival time of the application packet with said entry point when saidentry point is assigned to any of said at least one application packet.23. A recording apparatus using an information medium, the informationmedium including a data area configured to store at least one dataobject having record information, and a management area configured tostore management information for managing said at least one data object,and in which said management information includes program chaininformation configured to specify a manner of presentation of said atleast one data object, wherein said program chain information includesat least one piece of cell information, and wherein said cellinformation has an area configured to describe entry pint information ofat least one entry point, each entry point marking an arbitrary positionin said record information for a user to freely set contents of said atleast one data object, the recording apparatus comprising: means forrecording said record information in the data area of the informationmedium and means for entering said entry points with a predeterminedtime interval when said record information is recorded.
 24. Areproducing apparatus using an information medium, the informationmedium including a data area configured to store at least one dataobject having record information, and a management area configured tostore management information for managing said at least one data object,and in which said management information includes program chaininformation configured to specify a manner of presentation of said atleast one data object, wherein said program chain information includesat least one piece of cell information, and wherein said cellinformation has an area configured to describe entry point informationof at least one entry point, each entry point marking an arbitraryposition in said record information for a user to freely set contents ofsaid at least one data object, the reproducing apparatus comprising:means for reading information of at least one entry point from saidmanagement information; and means for converting a presentation time ofthe at least one entry point to a correspondence file access pointer inorder to access said at least one entry point when a presentation orplayback of said at least one entry point is required.